Illegal to drive with side lights?
Justin Dillon
Hi folks,
My colleagues tell me it is illegal to have your side lights
on while driving, and they should only be left on while parked. If this
is
the case I am sorry to say that I broke the law on my drive to work
this morning.
Can anyone confirm this, and, if so, explain some of the logic behind
the
rule,
All the best,
Justin.
--
Justin Dillon jud...@nortel.ca
Telecoms Software Engineer | Views expressed here are my own, and are
NORTEL, NITEC, Belfast | not necessarily those of my employer.
Thomas Sippel - Dau
In article <31F87B...@bnr.ca>, Justin Dillon <jud...@bnr.ca> writes:
-
- My colleagues tell me it is illegal to have your side lights
- on while driving, and they should only be left on while parked. If this
- is
- the case I am sorry to say that I broke the law on my drive to work
- this morning.
They are wrong. The side lights are required to be on when the main
lights are on. It is not illegal to drive just because the side lights
are on.
Thomas
--
*** Why not use metric units and get things right first time, every time.
* email: cma...@ic.ac.uk (Thomas Sippel - Dau)
* voice: +44 171 594 6904 (day), +44 171 594 6958 (fax), +44 171 385 6540
* snail: ICSTM, Computing Services, Kensington SW7 2BX, Great Britain
John Stumbles
On Fri, 26 Jul 1996, Justin Dillon wrote:
> My colleagues tell me it is illegal to have your side lights
> on while driving, and they should only be left on while parked. If this
> is
> the case I am sorry to say that I broke the law on my drive to work
> this morning.
>
> Can anyone confirm this, and, if so, explain some of the logic behind
> the
> rule,
Shows how many people read the Highway Code, except when they're studying
for their test :-)
For half an hour after sunset you use your sidelights, after that use
headlights.
(My wife's doing her test, so we had to look this up recently!)
--
John Stumbles j.d.st...@reading.ac.uk
Computer Services, University of Reading http://www.rdg.ac.uk/~suqstmbl
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
I'd rather be gardening
A. Grant
On Fri, 26 Jul 1996, Justin Dillon wrote:
> My colleagues tell me it is illegal to have your side lights
> on while driving, and they should only be left on while parked.
You are confused. The legislation says that it is no longer
legal to make cars with "side lights" which are literally that.
On modern cars when you switch on side lights the light comes
out of the main headlight unit.
Mark Gould
On Mon, 29 Jul 1996 17:59:50 +0100, in uk.transport,
Simon Culverhouse (10133...@compuserve.com) wrote:
: As far as I know, all new cars since about 1986 must run DIM-dip
: headlights when the engine and the side lights are on. This means that a
: resistor is used to power the main dipped lights at a lower power.
I think this was a good rule, especially as sidelights are too dim for
night-time running, and dipped lights are really too bright for most urban
use. Unfortunately, the European Court of Justice took a dim view of the
UK introducing the rule unilaterally, and so it no longer applies (that
is, it is not required for new cars to have dim-dip capability). If the
other EU member states come round to our way of thinking perhaps we will
see it again.
: I believe that day-running lights (dim-dip, not side lights) should be
: made law in the UK. The army use them, the Scandinavians use them after
: they found less accidents with them. Dutch drivers also drive with lights
: during the day, especially in the UK. Just think of children and older
: people on early winter mornings and evenings. The last thing school kids
: think of is road safety, I was there not too long ago. We need to give
: then every chance we can. What makes my blood boil is people who drive
: around in bad conditions with out any lights, be it at dawn/dusk or on a
: grey rainy day. IDIOTS the lot of them !!
Whilst I agree with much of what you say (especially as I have a
road-coloured car), I think that as many drivers go for over-illumination
as do for under-illumination. In situations where motor vehicles are
running on modern, bright, dipped lights where the ambient light level is
otherwise quite high (such as well-lit city streets and at dawn or dusk),
it can become difficult to see those road and pavement users who have
little or no illumination.
Mark.
--
| Mark Gould, Department of Law, University of Bristol |
| Mark....@bris.ac.uk | http://www.bris.ac.uk/%7Elwmdcg |
Karl Meyer
Justin Dillon wrote:
>
> Hi folks,
>
> My colleagues tell me it is illegal to have your side lights
> is
> the case I am sorry to say that I broke the law on my drive to work
> this morning.
>
> Can anyone confirm this, and, if so, explain some of the logic behind
> the
> rule,
>
Ths would have made all pre 86 (ish) volvos illegal as they always had them on.
On the otherhand maybe some retrospective legislation is required ;)
--
Karl Meyer +44 (0) 1223 250131
UUNET PIPEX Email:karl....@uunet.pipex.com
Internet House www.uunet.pipex.com
332 Science Park
Cambridge CB4 4WA
Tony Ashton
>On Mon, 29 Jul 1996 John Stumbles wrote
>On Fri, 26 Jul 1996, Justin Dillon wrote:
>> My colleagues tell me it is illegal to have your side lights
>> on while driving, and they should only be left on while parked. If thi
s>> is
>> the case I am sorry to say that I broke the law on my drive to work
>> this morning.
>>
>> Can anyone confirm this, and, if so, explain some of the logic behind
>> the
>> rule,
>Shows how many people read the Highway Code, except when they're studying
>for their test :-)
>For half an hour after sunset you use your sidelights, after that use
>headlights.
>snipped I'd rather be gardening
The Highway Code is, as its name implies, is a statement of recommended
practice - it is not necessarily a statement of the law.
I suggest that the original question should have been, "is it illegal to have
ONLY your side lights on while driving?" as they could be on with the
headlights as well. Many cars now incorporate a feature
whereby, if the engine is running, switching on only the side lights
nevertheless also automatically brings on dipped headlights.
The question is also interesting because it is not clear if Justin
starts work very early (i.e. before dawn) or if he drove in the daytime with
only side lights on and, if so, would that be illegal?
Tony Ashton
All views expressed are personal
Mark Gould
On 30 Jul 1996 08:18:06 GMT, in uk.transport,
Graham Berry (g.j....@dundee.ac.uk) wrote:
: I recently had the use of a hired Rover 416 for a week (wasn't too
: impressed, but that's another story), and in the owner's manual, there is
: a statement to the effect that dim-dip headlamps do not produce
: sufficient light output to comply with UK lighting regulations. This
: implies that if you need lights on at all, then you must use dipped beam,
: rather than dim-dip. Presumably it's OK to run during daylight hours
: with the dim-dip lamps on, that is when you don't legally require to
: display lights but decide to do so for reasons of safety.
I find that difficult to believe. The Road Vehicles Lighting Regulations
1989 (SI 1989/1769) state (reg.24) that when using a vehicle between
sunset and sunrise (and at some other times) all the position lamps (and
the registration plate lamp and end-outline marker lamp) should be
illuminated. The position lamps are what are commonly called the
side-lights and tail-lights, and are not required to be very bright.
Either the regulations have been changed (not to my knowledge), or Rover
have some very dim lights, or they were telling fibs. I suspect that, in
fact, they were not dim-dip lamps (which are not required by law, and are
specifically not part of European type approval) and they were referring
to the lowest headlamp setting. Although why they should build a car
which does not meet UK lighting specifications is beyond me.
Thomas Sippel - Dau
In article <DvD0L...@fsa.bris.ac.uk>, lwm...@mail.bris.ac.uk (Mark Gould) writes:
- On 30 Jul 1996 13:11:39 GMT, in uk.transport,
- Thomas Sippel - Dau (vul...@imperial.ac.uk) wrote:
- : Funnily I believe every word of it. It is another case of fairly close
- : regulation coupled with idiot-proof formulation of instructions.
....
- You don't appear to have read what I paraphrased from the regulations.
I did read (and understand!) what you said, my point was that
o following regulations to the letter (regardless of what they say)
o improving over established practice (no dim-dip lights in this case)
o formulating instructions so that the average dimwit understands them
correctly, or at least in such a way that a hostile lawyer cannot sue
you for leading said dimwit into commiting an offence
is soomewhat more difficult than squaring a circle and growing parsley in it.
It appears Rover tried and failed to come up with something, so they erred
on the side of safe advice.
....
- On that basis, there is no car which is constructed for European type
- approval which would fall foul of the regulation ...
I should hope not, nor did I want to have a go at you...
Thomas Sippel - Dau
In article <DvCLK...@fsa.bris.ac.uk>, lwm...@mail.bris.ac.uk (Mark Gould) writes:
- On 30 Jul 1996 08:18:06 GMT, in uk.transport,
- Graham Berry (g.j....@dundee.ac.uk) wrote:
-
- : I recently had the use of a hired Rover 416 for a week, ... and in
- : the owner's manual, there is a statement to the effect that dim-dip
- : headlamps do not produce sufficient light output to comply with UK
- : lighting regulations....
-
- I find that difficult to believe. The Road Vehicles Lighting Regulations
- 1989 (SI 1989/1769) state (reg.24) that when using a vehicle between
- sunset and sunrise (and at some other times) all the position lamps (and
- the registration plate lamp and end-outline marker lamp) should be
- illuminated. The position lamps are what are commonly called the
- side-lights and tail-lights, and are not required to be very bright.
Funnily I believe every word of it. It is another case of fairly close
regulation coupled with idiot-proof formulation of instructions. Once
that is in place, there is very little anybody can do for "improvement".
Take lights, there are big and small ones. They are on or off. That is
sort of the minumum acceptable knowledge that you must be able to show
before they take your driving licence away, in the latter case you are no
longer relevant for being regulated.
So, to make cars uniform across Europe, the small lights are 5 Watt
(sidelights, taillights, numberplate illumination), the big ones are
60/55 Watt (halogen headlights), 45/40 (Argon lights) or 21 W (brake,
reverse, back fog, indicator). They come in bulbs you get everywhere
across Europe, and if you put them in and they work you have a legally
lighted car. They are constructed so that you cannot place them in the
wrong receptacle.
There is some more in the way of regulation, but that is generally
enforced only during the type approval process, as an end user you
have a Right to Be Stupid and still not make mistakes that can be
construed as offences or illegal actions.
Now this has to be codified in regulations. If the regulation actually
mentions the wattage, then high efficiency LED displays are out, since
at the same wattage they dazzle, and at the same light output do not
conform to the letter of the regulation. Bicycle light regulations seem
just at the moment to be going through a process of adaption to LEDs.
Also, high level brake lights seem to be introduced as LEDs now.
- Either the regulations have been changed (not to my knowledge), or Rover
- have some very dim lights, or they were telling fibs.
Since dim-dip headlights are not required there cannot be a regulation
when you have to use them. If a regulation says dipped headlights at
night, then dim-dip is not enough because it does not conform to the
brightness of dipped headlights.
In fact, I don't know how bright they should be, by a 50% dimmed halogen
dipped headlight will probably create the same light and dazzle as a
full power dipped Argon headlight with a bulb near the end of its useful
life or a dirty reflector. But type approval is one thing, acceptable
performance before you fail an MOT quite another.
If you think how much regulation dim-dip could require I am not surprised
that nobody seems to have gone for setting it all out.
Rover was probably just formulating defensively so that people who did
not know what dim-dip is could just decide to ignore everything the
instruction manual said and still stay legal across Europe.
Graham Berry
In article <01bb7d70.cacf1a00$cdf982c1@culversi> Simon Culverhouse,
10133...@compuserve.com writes:
> As I have a
>1994 Rover 400 (which runs the lights when the engine is on), switching on
>the side lights brings on the dim-dip head lights.
I recently had the use of a hired Rover 416 for a week (wasn't too
impressed, but that's another story), and in the owner's manual, there is
a statement to the effect that dim-dip headlamps do not produce
sufficient light output to comply with UK lighting regulations. This
implies that if you need lights on at all, then you must use dipped beam,
rather than dim-dip. Presumably it's OK to run during daylight hours
with the dim-dip lamps on, that is when you don't legally require to
display lights but decide to do so for reasons of safety.
GB
Dr. Graham Berry
Dept of Applied Physics and Electronic and Mechanical Engineering
University of Dundee
Scotland, UK
"Bring not bagpipes to a man in trouble" - Old Scottish proverb.
Mark Gould
On 30 Jul 1996 13:11:39 GMT, in uk.transport,
: - I find that difficult to believe. The Road Vehicles Lighting Regulations
: - 1989 (SI 1989/1769) state (reg.24) that when using a vehicle between
: - sunset and sunrise (and at some other times) all the position lamps (and
: - the registration plate lamp and end-outline marker lamp) should be
: - illuminated. The position lamps are what are commonly called the
: - side-lights and tail-lights, and are not required to be very bright.
:
: Funnily I believe every word of it. It is another case of fairly close
: regulation coupled with idiot-proof formulation of instructions. Once
: that is in place, there is very little anybody can do for "improvement".
[snip]
: So, to make cars uniform across Europe, the small lights are 5 Watt
: (sidelights, taillights, numberplate illumination), the big ones are
: 60/55 Watt (halogen headlights), 45/40 (Argon lights) or 21 W (brake,
: reverse, back fog, indicator). They come in bulbs you get everywhere
: across Europe, and if you put them in and they work you have a legally
: lighted car. They are constructed so that you cannot place them in the
: wrong receptacle.
[snip]
: - Either the regulations have been changed (not to my knowledge), or Rover
: - have some very dim lights, or they were telling fibs.
:
: Since dim-dip headlights are not required there cannot be a regulation
: when you have to use them. If a regulation says dipped headlights at
: night, then dim-dip is not enough because it does not conform to the
: brightness of dipped headlights.
You don't appear to have read what I paraphrased from the regulations.
They require only that position lamps (side-lights) be used when in motion
between the hours of sunset and sunrise. I haven't got the regulations in
front of me, but I suspect that all side-lights which meet type approval
standards (the 5 watt ones) would suffice. On that basis, there is no car
which is constructed for European type approval which would fall foul of
the regulation, so long as its owner had turned the light switch to the
first position (minimal illumination).
Neither dipped headlights nor anything brighter than 'position lamps' (plus
ancilliaries) is required to satisfy the legal requirements of night-time
illumination.
Martin Briscoe
In message <DvBvn...@fsa.bris.ac.uk>
lwm...@mail.bris.ac.uk (Mark Gould) writes:
> On Mon, 29 Jul 1996 17:59:50 +0100, in uk.transport,
> Simon Culverhouse (10133...@compuserve.com) wrote:
> : As far as I know, all new cars since about 1986 must run DIM-dip
> : headlights when the engine and the side lights are on. This means that a
> : resistor is used to power the main dipped lights at a lower power.
> I think this was a good rule, especially as sidelights are too dim for
> night-time running, and dipped lights are really too bright for most urban
> use. Unfortunately, the European Court of Justice took a dim view of the
> UK introducing the rule unilaterally, and so it no longer applies (that
> is, it is not required for new cars to have dim-dip capability). If the
> other EU member states come round to our way of thinking perhaps we will
> see it again.
That makes sense as my Clio does not seem to have dim / dip. The
sidelights are quite bright and illuminate the whole of the headlight
area, but they are same with or without the engine running.
Someone mentioned the army using daytime running lights - I think its
more a case of them using headlights when in convoy, to identify the
other vehicles in the convoy rather than being visible to other road users.
--
---- Martin Briscoe - Fort William - Inverness-shire ----
-------------- martin....@zetnet.co.uk --------------
John Wright
>As far as I know, all new cars since about 1986 must run DIM-dip
>headlights when the engine and the side lights are on. This means that a
>resistor is used to power the main dipped lights at a lower power. What I
>have noticed is that too many people (particularly in pre-86 cars) drive
>with small side lights on (Volvo 240s, Metros, etc.) when they should be
>using dipped lights.
On the Volvo 240, the side lights come on with the ignition. The next
position after "off" on the light switch brings in just such a dim-dip
system. The final position brings on full power headlamps. Most people
probably aren't aware of these rules, I wasn't until I read this thread.
If people driving Volvo 240's don't use the dim-dip position more often,
it's probably because this is the only light switch position which leaves
the side lights on with the ignition off. Laziness, I guess.
[snip]
>I believe that day-running lights (dim-dip, not side lights) should be
>made law in the UK. The army use them, the Scandinavians use them after
>they found less accidents with them.
About 1982 or thereabouts when Volvo and SAAB introduced the scheme I
describe, they believed that having the side lights *only* on reduced
accidents by improving car visibility. Perhaps they now believe that using
day running lights gives a further benefit in this area.
[snip]
--
John Wright
Time is an illusion, lunchtime doubly so - Ix (Ford Prefect)
Fingerprint = D3 80 D9 38 F8 C9 D9 86 6B F1 DC F5 56 DF BC 82
Mark Gould
On 30 Jul 1996 16:04:21 GMT, in uk.transport,: In article <DvD0L...@fsa.bris.ac.uk>, lwm...@mail.bris.ac.uk (Mark Gould) writes:
: - On 30 Jul 1996 13:11:39 GMT, in uk.transport,
: - Thomas Sippel - Dau (vul...@imperial.ac.uk) wrote:
:
: - : Funnily I believe every word of it. It is another case of fairly close
: - : regulation coupled with idiot-proof formulation of instructions.
: ....
: - You don't appear to have read what I paraphrased from the regulations.
:
: I did read (and understand!) what you said, my point was that
Sorry -- I misunderstood what you meant.
: o following regulations to the letter (regardless of what they say)
:
: o improving over established practice (no dim-dip lights in this case)
I stated before that I am not convinced that more illumination is always
better, so I would disagree that dipped lights are an improvement over
dim-dips.
: o formulating instructions so that the average dimwit understands them
: correctly, or at least in such a way that a hostile lawyer cannot sue
: you for leading said dimwit into commiting an offence
:
: is soomewhat more difficult than squaring a circle and growing parsley in it.
:
: It appears Rover tried and failed to come up with something, so they erred
: on the side of safe advice.
Albeit advice which rendered their fitting of dim-dips in the first place
(if indeed they were fitted) almost completely pointless.
Hugh Barrass
> Justin Dillon wrote:
> >
> > Hi folks,
> >
> > on while driving, and they should only be left on while parked. If this
> > is
> > the case I am sorry to say that I broke the law on my drive to work
> > this morning.
> >
> > Can anyone confirm this, and, if so, explain some of the logic behind
> > the
> > rule,
> >
I can confirm it is illegal
(in California)
The only possible way round it is to put a sticker over the "parking lights"
switch that says, "daytime running lights."
I don't think it's in the UK laws and I can't think of any reason behind
it. Perhaps some californians were driving around with parking lights
on, thought they were parked and tried to get out of the car...
Hugh.
In some cities (particularly Edinburgh & Aberdeen) I've seen a lot of
people driving on sidelights at night - this is also quite dangerous
as it can cause other road users to misjudge the distance (a friend of
mine was hit because of that). The argument is that the street lighting
enables you to see adequately, so headlights are unnecessary.
--
Hugh Barrass | These views are mine & mine alone!
Cisco Systems Inc |
170 W. Tasman Drive | There are more interesting things in life...
San Jose, Ca 95134-1706 |
408-527-3084 |
John Wright
On Tue, 30 Jul 1996 16:33:30 -0700, Hugh Barrass wrote:
>> Justin Dillon wrote:
>> > My colleagues tell me it is illegal to have your side lights
>> > on while driving, and they should only be left on while parked. If this
[snips]
>I don't think it's in the UK laws and I can't think of any reason behind
>it. Perhaps some californians were driving around with parking lights
>on, thought they were parked and tried to get out of the car...
The *last* Highway Code (1993 edition - i.e. not the new one) says the
following (Excerpting relevant bits about use of lights):
You MUST:
- use sidelights between sunset and sunrise;
- use headlights at night (between half an hour after sunset and half an
hour before sunrise) on all roads without street lighting and on roads
where the street lights are more than 185 metres (600ft) apart or are not
lit;
- use headlights or front fog lights when visibility is seriously reduced,
generally when you cannot see for more than 100 metres (328 ft).
You should also:
- use headlights at night on lit motorways and road with a speed limit in
excess of 50 mph;
- use dipped headlights at night in built up areas unless the road is well
lit;
- cut down glare. If your vehicle has dim-dip, use it instead of dipped
headlights in dull daytime weather and at night in built up areas with good
street lighting;
There is no "must not" about side lights when driving, indeed they are
compulsory under certain conditions as a minimum
HTH
Graham Berry
In article <199607310...@zetnet.co.uk> Martin Briscoe,
martin....@zetnet.co.uk writes:
>That makes sense as my Clio does not seem to have dim / dip. The
>sidelights are quite bright and illuminate the whole of the headlight
>area, but they are same with or without the engine running.
Yes, I notice Renault have stopped fitting dim-dip in the last couple of
years. My 21 (1991) has dim-dip fitted, but it's successor, the Laguna,
has not.
I was also under the impression that if lights are required at all, then
they must be headlamps, rather than just sidelights, but I stand
corrected (see Mark Gould's posting).
John Wright
On 31 Jul 1996 11:44:21 GMT, c...@aisb.ed.ac.uk (Chris Malcolm) wrote:
> John Wright writes:
>>About 1982 or thereabouts when Volvo and SAAB introduced the scheme I
>>describe, they believed that having the side lights *only* on reduced
>>accidents by improving car visibility. Perhaps they now believe that using
>>day running lights gives a further benefit in this area.
>Anything which makes Volvos easier to recognise will reduce accidents.
That could of course have been the other reason :-)))
Alan J Holmes
In article <31ff1971...@news.rl.ac.uk>,
John Wright <j...@isise.rl.ac.uk> wrote:
Stuf deleted:-
>There is no "must not" about side lights when driving, indeed they are
>compulsory under certain conditions as a minimum
But should we have legislation against the use of
headlights during daylight hours when the visibility is
good?
Alan
Alan J Holmes
In article <01bb7d70.cacf1a00$cdf982c1@culversi>,
Simon Culverhouse <10133...@compuserve.com> wrote:
Stuff deleted:-
>I believe that day-running lights (dim-dip, not side lights) should be
>made law in the UK. The army use them, the Scandinavians use them after
>they found less accidents with them. Dutch drivers also drive with lights
>during the day, especially in the UK. Just think of children and older
>people on early winter mornings and evenings. The last thing school kids
>think of is road safety, I was there not too long ago. We need to give
>then every chance we can. What makes my blood boil is people who drive
>around in bad conditions with out any lights, be it at dawn/dusk or on a
>grey rainy day. IDIOTS the lot of them !!
What has the use of headlights during the daytime have to
do with dark winter moronigs and evenings?
I think there should be legislation _against_ the use of
headlights during clear daylight.
Alan
Simon Culverhouse
(snip)
> >I believe that day-running lights (dim-dip, not side lights) should be
> >made law in the UK. The army use them, the Scandinavians use them
after
> >they found less accidents with them. Dutch drivers also drive with
lights
> >during the day, especially in the UK. Just think of children and older
> >people on early winter mornings and evenings. The last thing school
kids
> >think of is road safety, I was there not too long ago. We need to give
> >then every chance we can. What makes my blood boil is people who drive
> >around in bad conditions with out any lights, be it at dawn/dusk or on
a
> >grey rainy day. IDIOTS the lot of them !!
>
> What has the use of headlights during the daytime have to
> do with dark winter moronigs and evenings?
inconsiderate, DANGEROUS idiots out there, if the lights came on
automatically, then they would not have go to the great effort of finding
the switch. Maybe there would be less deaths on the road from pedestrians
to people pulling out of junctions because they did not see the vehicle
approaching.
>
> I think there should be legislation _against_ the use of
> headlights during clear daylight.
>
that the Swedish government (and the rest). I will pass your comments on
to them.
> Alan
>
--
Simon Culverhouse
10133...@compuserve.com
Simon Culverhouse
> Alan....@brunel.ac.uk (Alan J Holmes) wrote in article
<4tsmks$8...@loki.brunel.ac.uk>...
NO !!! I always use dipped lights on motorways so that a simple glance in
the mirror makes me instantly visible. After a close shave with death
where some idiot pulled out on me as I was about to pass, and I can only
assume he/she did not see me, I now do all I can to be visible when
traveling at such speeds. The Scandinavians introduced day-running lights
after they had solid proof that using them reduced accidents. It is true
that in certain parts of Scandinavia the winter days are short, but it is
law there to use then in all conditions all year round. I have more trust
and respect for what the Swedish government recommends as opposed any
British advice. From what I have seen of northern European driving, the
British must be some of the worst !!
--
Simon Culverhouse
10133...@compuserve.com
Martin Briscoe
In message <4tsmso$8...@loki.brunel.ac.uk>
Alan....@brunel.ac.uk (Alan J Holmes) writes:
> In article <01bb7d70.cacf1a00$cdf982c1@culversi>,
> Simon Culverhouse <10133...@compuserve.com> wrote:
> Stuff deleted:-
> >I believe that day-running lights (dim-dip, not side lights) should be
> >made law in the UK. The army use them, the Scandinavians use them after
> What has the use of headlights during the daytime have to
> do with dark winter moronigs and evenings?
> I think there should be legislation _against_ the use of
> headlights during clear daylight.
Its bad enoughtrying to get people to put on lights of any sort
during twilight, heavy rain, snow or fog. It would be even worse if
they were worrying about getting nicked for putting on too early.
My policy is to make my own vehicle as visible as possible on the
road - this includes use of lights and reflectivity around it. I
would prefer a more visible colour but I am stuck with what was
available when I bought it.
Incidentally I always wonder why manufacturers don't use a bit more
reflectivity around cars, there have been in the past fashions for
"go-faster" stripes, model names etc down the side of the car. If
these were done in reflective material they would also make the
vehicle much more visible at night.
Scott Walker
"Simon Culverhouse" <10133...@compuserve.com> wrote:
>From what I have seen of northern European driving, the
>British must be some of the worst !!
I know its bad, but worse than Belguim? No way!!
Scott Walker
_________________________________________________________
Nottingham, UK sc...@innotts.co.uk
Paul Marsden
In article <01bb8099.570c5c00$9ef982c1@culversi> Simon Culverhouse,
10133...@compuserve.com writes:
>Nothing !!! But now that you mention it, for all hose lazy,
>inconsiderate, DANGEROUS idiots out there, if the lights came on
>automatically, then they would not have go to the great effort of finding
>the switch. Maybe there would be less deaths on the road from pedestrians
>to people pulling out of junctions because they did not see the vehicle
>approaching.
I think that you have the wrong end of the stick here.
It is not the job of the pedestrian to look out for cars.
The car driver has the responsibility to avoid pedestrians, dogs, cats,
horses, hedgehogs etc.
How does someone who is BLIND look out for cars.
It is car drivers in towns with headlights on that cause the problem.
Headlights DO cause dazzle, both to pedestrians and other car drivers.
The use of dipped headlights limits ones clear vision to the area of the
beam. It also makes it difficult for myself to see behind the car driving
on headlights.
BTW pedestrians have right of way unless otherwise stated at junctions
Simon Culverhouse
(snip)
>
>
> I think that you have the wrong end of the stick here.
> It is not the job of the pedestrian to look out for cars.
> The car driver has the responsibility to avoid pedestrians, dogs, cats,
> horses, hedgehogs etc.
> How does someone who is BLIND look out for cars.
>
> It is car drivers in towns with headlights on that cause the problem.
> Headlights DO cause dazzle, both to pedestrians and other car drivers.
> The use of dipped headlights limits ones clear vision to the area of the
> beam. It also makes it difficult for myself to see behind the car driving
> on headlights.
>
> BTW pedestrians have right of way unless otherwise stated at junctions
>
You are absolutely right, drivers are fully responsible. But, that is no
consolation to someone who has been knocked over by a car. On my way to
work in the mornings, I notice only to clearly the behavior of certain
groups of pedestrians, especially school children. I also remember only
too clearly the difference I felt as a pedestrian after I had learnt to
drive (and it was not that long ago). Once you are a _regular_ car driver,
you tend to pay attention to all objects around you, not just other people
on the pavement. I my self have often looked both ways at a junction, and
only when checking for a final time before moving did I notice another
vehicle and this happens mainly in the twilight hours, etc.
I agree that lights can dazzle in certain conditions. However, during the
day, I have never been dazzled by dim-dip lights and one thing I know for
sure, when a line of cars approach me, the vehicle with lights (dim-dip
usually) catches my attention first. Either way, I nor several European
governments suddenly woke up one day and said "Hey day-running lights are a
great idea". It is all based on rational judgment, based on facts
available. And just because our government does not come to the same
conclusions it does not mean that they are right. After all, when was the
last time our government ever examined what was done in other parts of the
world (if we didn't think of it, we don't want to know !).
--
Simon Culverhouse
simon.cu...@dial.pipex.com
Chris Malcolm
In article <01bb83c4$56ae1ae0$LocalHost@culversi> "Simon Culverhouse" <simon.cu...@dial.pipex.com> writes:
> ... one thing I know for
>sure, when a line of cars approach me, the vehicle with lights (dim-dip
>usually) catches my attention first.
One thing I know for sure is that when a gang of pedestrians approaches
only one of whom is wearing a green T-shirt, the one wearing a green
T-shirt catches my attention first.
>It is all based on rational judgment, based on facts available.
So let's make pedestrians all wear green. Research shows that those
wearing green stand out, so it stands to reason.
Did you ever hear of the arms race? We have just started the conspicuity
race....
--
Chris Malcolm c...@aifh.ed.ac.uk +44 (0)131 650 3085
Department of Artificial Intelligence, Edinburgh University
5 Forrest Hill, Edinburgh, EH1 2QL, UK DoD #205
"The mind reigns, but does not govern" Paul Valery
Dean B.
In article <320833e7...@news.rl.ac.uk>, j...@isise.rl.ac.uk (John
Wright) wrote:
> On 6 Aug 1996 22:07:12 GMT, c...@aisb.ed.ac.uk (Chris Malcolm) wrote:
> >Simon Culverhouse writes:
>
> >> ... one thing I know for
> >>sure, when a line of cars approach me, the vehicle with lights (dim-dip
> >>usually) catches my attention first.
> >
> >One thing I know for sure is that when a gang of pedestrians approaches
> >only one of whom is wearing a green T-shirt, the one wearing a green
> >T-shirt catches my attention first.
> >
> >>It is all based on rational judgment, based on facts available.
> >
> >So let's make pedestrians all wear green. Research shows that those
> >wearing green stand out, so it stands to reason.
>
> Why not therefore paint all cars fluorescent orange? After all, we motor
> cyclists are recommended to make prats of ourselves by wearing dayglo
> belts....
Why not scrap the noise regulations on cars? Since getting my TVR, I've
noticed a significant decrease in 'lemmings' ambling across the road in
front of me looking the other way. Anyway, I don't fancy British Racing
Orange as a colour...
Dean
John Wright
>> ... one thing I know for
>>sure, when a line of cars approach me, the vehicle with lights (dim-dip
>>usually) catches my attention first.
>
>One thing I know for sure is that when a gang of pedestrians approaches
>only one of whom is wearing a green T-shirt, the one wearing a green
>T-shirt catches my attention first.
>
>>It is all based on rational judgment, based on facts available.
>
>So let's make pedestrians all wear green. Research shows that those
>wearing green stand out, so it stands to reason.
Why not therefore paint all cars fluorescent orange? After all, we motor
cyclists are recommended to make prats of ourselves by wearing dayglo
belts....
What was the old slogan? "Fight back - wear black" :-)
Alan J Holmes
In article <01bb8096.66b97320$9ef982c1@culversi>,
Simon Culverhouse <10133...@compuserve.com> wrote:
>> Alan....@brunel.ac.uk (Alan J Holmes) wrote in article
><4tsmks$8...@loki.brunel.ac.uk>...
>> In article <31ff1971...@news.rl.ac.uk>,
>> John Wright <j...@isise.rl.ac.uk> wrote:
>> Stuf deleted:-
>> >There is no "must not" about side lights when driving, indeed they are
>> >compulsory under certain conditions as a minimum
>> But should we have legislation against the use of
>> headlights during daylight hours when the visibility is
>> good?
>NO !!! I always use dipped lights on motorways so that a simple glance in
>the mirror makes me instantly visible. After a close shave with death
>where some idiot pulled out on me as I was about to pass, and I can only
>assume he/she did not see me, I now do all I can to be visible when
>traveling at such speeds. The Scandinavians introduced day-running lights
>after they had solid proof that using them reduced accidents. It is true
>that in certain parts of Scandinavia the winter days are short, but it is
>law there to use then in all conditions all year round. I have more trust
>and respect for what the Swedish government recommends as opposed any
>British advice. From what I have seen of northern European driving, the
>British must be some of the worst !!
But there are certain dangers when using headlights during the
daytime, it has become acceptable that quick flashes of
headlights means 'come on, I'm giving way to you', if you see a
vehicle with it's lights on during the day and he goes over a
bump, the lights appear to flash inviting someone to come out of
a side road into your path.
Also the lights cost fuel to run, this adds to the emmisions from
the exhaust and makes the hole in the ozone layer worse.
Alan
Simon Culverhouse
Chris Malcolm <c...@aisb.ed.ac.uk> wrote in article
<4u8fmg$q...@scotsman.ed.ac.uk>...
> In article <01bb83c4$56ae1ae0$LocalHost@culversi> "Simon Culverhouse"
<simon.cu...@dial.pipex.com> writes:
>
> > ... one thing I know for
> >sure, when a line of cars approach me, the vehicle with lights (dim-dip
> >usually) catches my attention first.
>
> One thing I know for sure is that when a gang of pedestrians approaches
> only one of whom is wearing a green T-shirt, the one wearing a green
> T-shirt catches my attention first.
Very good. When was the last time 1.5 tonnes of pedestrian, traveling at
30 - 70mph hit someone who had their thoughts elsewhere and stepped out in
front of them. Talk sense will you. Incidentally, why do aircraft use
light (landing / T/O) in broad daylight ? Could it be to make them clearly
visible. And why do the Scandinavians use day-running lights ? Probably
just to irritate :)
--
Simon Culverhouse
simon.cu...@dial.pipex.com
Alan J Holmes
In article <01bb8489$45a8d8a0$LocalHost@culversi>,
Simon Culverhouse <simon.cu...@dial.pipex.com> wrote:
> Incidentally, why do aircraft use
>light (landing / T/O) in broad daylight ? Could it be to make them clearly
>visible.
There's a good question, why do aircraft use landing
lights in daylight, could it be to show that they are
landing, not just passing by?
> And why do the Scandinavians use day-running lights ? Probably
>just to irritate :)
Surely the question should be, why is it _only_ the
Scandiavians who use day time lights, perhaps it's
because they are such bad drivers, possibly half blind.
Alan
Marcus Jones
In article <4ua88u$8...@loki.brunel.ac.uk>, Alan....@brunel.ac.uk (Alan J Holmes) says:
>
>In article <01bb8096.66b97320$9ef982c1@culversi>,
>Simon Culverhouse <10133...@compuserve.com> wrote:
>>> Alan....@brunel.ac.uk (Alan J Holmes) wrote in article
>><4tsmks$8...@loki.brunel.ac.uk>...
>>> In article <31ff1971...@news.rl.ac.uk>,
>>> John Wright <j...@isise.rl.ac.uk> wrote:
>
>>> Stuf deleted:-
>
The Scandinavians introduced day-running lights
>>after they had solid proof that using them reduced accidents. It is true
>>that in certain parts of Scandinavia the winter days are short, but it is
>>law there to use then in all conditions all year round. I have more trust
>>and respect for what the Swedish government recommends as opposed any
>>British advice. From what I have seen of northern European driving, the
>>British must be some of the worst !!
Canada also has compulsory daytime lights. The benefits are
probably greater for Northern countries, but I still think it would
reduce accidents in the UK, at virtually zero cost and inconvenience.
>
>But there are certain dangers when using headlights during the
>daytime, it has become acceptable that quick flashes of
>headlights means 'come on, I'm giving way to you', if you see a
>vehicle with it's lights on during the day and he goes over a
>bump, the lights appear to flash inviting someone to come out of
>a side road into your path.
Stretching things a little aren't you?
>Also the lights cost fuel to run, this adds to the emmisions from
100 watts or thereabouts, for full headlights (which would not be used). Not
a huge cost. I think having low tyre pressure is more significant.
>the exhaust and makes the hole in the ozone layer worse.
What???????
Marcus
Tom Wheeley
In article <4upiql$l...@sun4.bham.ac.uk>
m.r....@bham.ac.uk "Marcus Jones" writes:
>
> >Also the lights cost fuel to run, this adds to the emmisions from
>
> 100 watts or thereabouts, for full headlights (which would not be used). Not
> a huge cost. I think having low tyre pressure is more significant.
>
> >the exhaust and makes the hole in the ozone layer worse.
>
> What???????
>
Don't forget Global Warming and the demise of the rainforests too!
(Isn't everything supposed to cause GW or Ozone holes these days? I always
thought the problem with cars was _too much_ ozone, not too little :-)
.splitbung http://www.tsys.demon.co.uk
--
* TQ 1.0 * The 'Just So Quotes'.
Drawing on my fine command of language, I said nothing.
-- Mark Twain
John Wright
>Don't forget Global Warming and the demise of the rainforests too!
>
>(Isn't everything supposed to cause GW or Ozone holes these days? I always
>thought the problem with cars was _too much_ ozone, not too little :-)
Ozone in the wrong place that's the trouble. It's *good* 60 or 70,000 feet
up, not so good 10 feet up... I suspect the real reason for killing all
these cows is not BSE or the threat therof, it's because it's known that
farting cows causes the biggest contribution to global warming.
Thomas Sippel - Dau
In article <4upiql$l...@sun4.bham.ac.uk>, M.R.Jo...@bham.ac.uk (Marcus Jones) writes:
- In article <4ua88u$8...@loki.brunel.ac.uk>, Alan....@brunel.ac.uk (Alan J Holmes) says:
-
- >Also the lights cost fuel to run, this adds to the emmisions from
-
- 100 watts or thereabouts, for full headlights (which would not be used). Not
- a huge cost. I think having low tyre pressure is more significant.
-
- >the exhaust and makes the hole in the ozone layer worse.
-
- What???????
I am surprised even Marcus can get exasperated at times. We live and learn.
Running on dipped lights needs:
2x headlights 110W (dipped)
2x sidelights 10W
2x taillights 12W
2x plate lights 10W (usually 2)
3x dashboard 15W
1x control light 5W
=======
162W
generator eff 0.8
ice engine eff 0.25 (partload)
================================
810 watt fuel burning requirement
I worked out that over the years 1986 to 91 the three bedroom house I
lived in had an average electricity consumption of 587W - both heating
and cooking with gas, though the central heating pump was electric ...
Thomas
--
*** Why not use metric units and get things right first time, every time.
* email: cma...@ic.ac.uk (Thomas Sippel - Dau)
* voice: +44 171 594 6904 (day), +44 171 594 6958 (fax), +44 171 385 6540
* snail: ICSTM, Computing Services, Kensington SW7 2BX, Great Britain
Marcus Jones
In article <4uvpt0$5...@oban.cc.ic.ac.uk>, vul...@imperial.ac.uk (Thomas Sippel - Dau) says:
>
>
>In article <4upiql$l...@sun4.bham.ac.uk>, M.R.Jo...@bham.ac.uk (Marcus Jones) writes:
>- In article <4ua88u$8...@loki.brunel.ac.uk>, Alan....@brunel.ac.uk (Alan J Holmes) says:
>-
>- >Also the lights cost fuel to run, this adds to the emmisions from
>-
>- What???????
>
>I am surprised even Marcus can get exasperated at times. We live and learn.
I am surprised that people STILL make dumb comments about
vehicle emissions affecting the ozone layer! The problems are
completely different! Need I spell it out?
OZONE DEPLETION
Reduction of stratospheric ozone concentrations caused by
ozone depleting chemicals like CFCs, and also to a lesser
extent by NOx emissions from high altitude aircraft. Ozone
depleting chemicals emitted at ground level need to have
a long lifespan in the atmosphere in order to leave the
troposhere. This is why CFCs are ozone depleters, but ground
level emissions of NO are not.
GREENHOUSE EFFECT
The retention of radiative heat in the atmosphere by chemicals
which are transparent to visible and short wavelength radiation
but which absorb the infra-red wavelengths. Greenhouse gases
include water, CO2, methane, CFCs and HCFCs.
SMOG AND POOR AIR QUALITY
The presence of chemicals in the troposphere at concentrations
which are harmful to living organisms or which in some other way
affect the quality of life. As these effects are related to the
concentration of the chemicals their impact is generally greater near
to their sources, which is not the case with greenhouse gases
or ozone depleters. Common pollutants include particles (PM10),
SO2, NOx, CO, hydrocarbons and tropospheric O3 formed by reaction
among the other pollutants. In urban areas vehicle emissions
are the main cause of poor air quality (see DoE Quality of
Urban Air Review Group (QUARG) reports 1993 and 1996).
There is clearly a considerable difference between those chemicals
which are alleged to cause global environemtal problems, and those
which create health problems. Lights have NOTHING to do with the
ozoen layer.
Now, lets move on to those lights...
>Running on dipped lights needs:
>
> 2x headlights 110W (dipped)
> 2x sidelights 10W
> 2x taillights 12W
> 2x plate lights 10W (usually 2)
> 3x dashboard 15W
> 1x control light 5W
> =======
> 162W
> generator eff 0.8
> ice engine eff 0.25 (partload)
> ================================
> 810 watt fuel burning requirement
>
These figures look reasonable, but the issue is not just about
fuel is it- it is about cutting accidents. Furthermore, if people
were that concerned about their petrol consumption they would
drive more efficent cars, they would check their tyre pressure
regularly and they would adopt a more efficient driving style.
Fuel savings of around 30% have been achieved in lorry fleets
by driver training and monitoring, without increasing journey
times (from an ETSU leaflet).
As far as I am concnerned, if driving with dipped headlights
reduces accidents, which experience in other
countries says it does (i've heard >10% fall in Denmark)
, then it should be compulsory. Road accidents are real, destroy
lives and harm the economy. This is far more important than
a negligable increase in CO2 emissions when the whole
greenhouse effect issue is far from certain anyway.
Marcus
Alan J Holmes
In article <4upiql$l...@sun4.bham.ac.uk>,
Marcus Jones <m.r....@bham.ac.uk> wrote:
>In article <4ua88u$8...@loki.brunel.ac.uk>, Alan....@brunel.ac.uk (Alan J Holmes) says:
>>Also the lights cost fuel to run, this adds to the emmisions from
>100 watts or thereabouts, for full headlights (which would not be used). Not
>a huge cost. I think having low tyre pressure is more significant.
I, some time ago, had to take a fuel consumption test on
my Escort, the tester said he and collegues had carried
out a number of tests for various loads on cars.
His experience was that a set of headlights switched on
resulted in an increased consumption of 3 miles per gallon of fuel.
Around 10% on most family cars.
Alan
Chris Snowdon
> 2x headlights 110W (dipped)
> 2x sidelights 10W
> 2x taillights 12W
> 2x plate lights 10W (usually 2)
> 3x dashboard 15W
> 1x control light 5W
> =======
> 162W
> generator eff 0.8
> ice engine eff 0.25 (partload)
> ================================
> 810 watt fuel burning requirement
Ermmm....I don't think it's quite that simple.
The engine is generating power to recharge the battery almost as a
by-product by turning an alternator. Much of this is dissipated as
heat if not used (hence the large fins on many voltage regulator
units). The alternator is turning regardless of whether you use it's
output so much of the energy is being used regardless of whether you
use your lights or not.....
C.
Chris Snowdon
Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>I, some time ago, had to take a fuel consumption test on
>my Escort, the tester said he and collegues had carried
>out a number of tests for various loads on cars.
>His experience was that a set of headlights switched on
>resulted in an increased consumption of 3 miles per gallon of fuel.
>Around 10% on most family cars.
If that is true then I find it astonishing. Surely the engine drives
the alternator regardless of whether your lights are on or off, or am
I missing something here ? How does using the current to light some
bulbs rather than dissipating it as heat through the regulator /
rectifier circuit contribute to increased petrol consumption ? Does
the torque needed to turn the alternator vary significantly as more
currrent is drawn ?
If the torque needed to turn the alternator does *not* vary with load
then the only way I can see that the lights would increase consumption
is if their use decreased the efficiency of the ignition system,
resulting in too-weak a spark and producing incomplete combusion.
I can't see this being plausible unless you had a dodgy battery or a
faulty charging circuit. In my experience much more current is
produced than can be used.....I've 'fried' two batteries on my bike in
the past and I *always* ride with lights on.
So, basically I would like to know how using the lights imposes an
extra load on the engine and results in decreased mpg.
Can anyone clarify this please ???????
C.
Chris Malcolm
In article <81b7cc$11a3...@news.wmc.ac.uk> csno...@wmc.ac.uk (Chris Snowdon) writes:
>Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>>I, some time ago, had to take a fuel consumption test on
>>my Escort, the tester said he and collegues had carried
>>out a number of tests for various loads on cars.
>>His experience was that a set of headlights switched on
>>resulted in an increased consumption of 3 miles per gallon of fuel.
>>Around 10% on most family cars.
>If that is true then I find it astonishing. Surely the engine drives
>the alternator regardless of whether your lights are on or off, or am
>I missing something here ?
Yes, basic physics.
>How does using the current to light some
>bulbs rather than dissipating it as heat through the regulator /
>rectifier circuit contribute to increased petrol consumption ?
No regulator takes the full alternator output and dissipates it as heat
when not used. To do that you'd need a large electric fire! Some
regulators do dissipate a little heat, maybe 5 watts on idle, a trivial
amount, and when passing large currents they might dissipate 5% of it,
that's why a heat sink is needed.
>Does
>the torque needed to turn the alternator vary significantly as more
>currrent is drawn ?
Of course it does! That's where the current comes from!
>In my experience much more current is
>produced than can be used.....I've 'fried' two batteries on my bike in
>the past and I *always* ride with lights on.
Because of a faulty regulator or shorting battery cells misleading the
regulator about the state of charge. It is physically impossible to
produce more current than is used. Note however, that some ancient bikes
(e.g. old Triumphs) used to use very cheap Lucas regulators which *did*
take the full alternator output and dump it in a zener. This system had
no virtue but cheapness -- it destroyed zeners, batteries, and bulbs,
regularly, and wasted petrol. It is no longer used.
>So, basically I would like to know how using the lights imposes an
>extra load on the engine and results in decreased mpg.
Exactly in the manner the original poster indicated. The extra current
requires more torque input to the alternator, which comes from the
engine, plus an extra percentage for friction and heat, which in turn
comes from the petrol, plus an extra percentage for friction and heat
again. Since some of the current comes from the battery (e.g. when
stopped at lights) and is put back again later by the alternator, you
have to add an extra factor too for the battery efficiency.
Lights don't come free.
Paul Abraham
Chris Snowdon wrote:
> The alternator is turning regardless of whether you use it's
> output so much of the energy is being used regardless of whether you
> use your lights or not.....
This is like saying that the engine is turning whether you are moving
or not. In this case you use as much fuel stationary as you do climbing a
steep hill at 50 (given the same revs I suppose).
No, to take more out you have to put more in; there's no such thing
as a free lunch. Its true that the alternator is not 100%
efficient and so you need some power simply to drive it (against friction
in the bearings, switching in the regulator etc), but the power required
for lights etc is over and above that.
Paul
Martin Gilbert
csno...@wmc.ac.uk (Chris Snowdon) wrote:
>Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>>His experience was that a set of headlights switched on
>>resulted in an increased consumption of 3 miles per gallon of fuel.
>>Around 10% on most family cars.
>If that is true then I find it astonishing. Surely the engine drives
>the alternator regardless of whether your lights are on or off, or am
>I missing something here ?
[snip discussion over the likelihood of this figure]
>Can anyone clarify this please ???????
Yes: Alan's talking crap. Again.
Martin Gilbert
--
"I've met plenty of people who can tell you the square root of a
pickled onion, if only they could get the lid off the jar."
-- Hugh Davies
Dan Glover
In article <4vv0bc$o...@scotsman.ed.ac.uk>, Chris Malcolm
<c...@aisb.ed.ac.uk> writes
>>>His experience was that a set of headlights switched on
>>>resulted in an increased consumption of 3 miles per gallon of fuel.
>
>>>Around 10% on most family cars.
>
>>If that is true then I find it astonishing. Surely the engine drives
>>the alternator regardless of whether your lights are on or off, or am
>>I missing something here ?
>
Being a believer more in practical experience than theory I suggest the
"proof" of the extra energy requirement can be demonstrated as follows:
After a longish run (to ensure the battery has recovered from starting
etc) switch on headlights while the engine is idling. The revs will be
seen (if you have a counter) and/or heard to fall slightly. To return
to the previous idle speed requires opening the throttle slightly -
result increase in fuel consumption. [1]
Obviously when on the move this effect is masked: one normally strives
to attain the desired speed rather than opening the throttle by a
measured amount.
Setting of idle speed and mixture is often specified with certain
conditions, eg cooling fan running, because of the effect of electrical
loads.
[big snip]
>Lights don't come free.
True, but I hope people aren't so tight as to not illuminate them when
appropriate for the conditions just to get a few more mpg!
Dan
[1] The effect may be masked if the engine is managed electronically and
automatically adjusts the idle speed back to normal - the experiment
certainly works on "simple" cars.
--
Dan Glover (d...@dangl.demon.co.uk)
Move along now, please! There's nothing more to see!
Jeremy Greenow
csno...@wmc.ac.uk (Chris Snowdon) wrote:
>Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>>I, some time ago, had to take a fuel consumption test on
>>my Escort, the tester said he and collegues had carried
>>out a number of tests for various loads on cars.
>>His experience was that a set of headlights switched on
>>resulted in an increased consumption of 3 miles per gallon of fuel.
>>Around 10% on most family cars.
>If that is true then I find it astonishing. Surely the engine drives
>the alternator regardless of whether your lights are on or off, or am
>I missing something here ?
You are.
> How does using the current to light some
>bulbs rather than dissipating it as heat through the regulator /
>rectifier circuit contribute to increased petrol consumption ? Does
>the torque needed to turn the alternator vary significantly as more
>currrent is drawn ?
Yes.
>If the torque needed to turn the alternator does *not* vary with load
>then the only way I can see that the lights would increase consumption
>is if their use decreased the efficiency of the ignition system,
>resulting in too-weak a spark and producing incomplete combusion.
>I can't see this being plausible unless you had a dodgy battery or a
>faulty charging circuit. In my experience much more current is
>produced than can be used.....I've 'fried' two batteries on my bike in
>the past and I *always* ride with lights on.
>So, basically I would like to know how using the lights imposes an
>extra load on the engine and results in decreased mpg.
Try it for youself: (I am assuming you have access to a car)
Sit in the car with the engine idling - foot off the accelerator - and
observe the rev counter or the engine note.
Now switch on some electrical gadgetry; lights, heated rear window,
etc.
You should notice a slight drop in the engine speed due to the
increased electrical load. QED
(This probably works better with smaller engined cars.)
Regards
--
______________________________________________________________
Jeremy Greenow j...@greenow.u-net.com
Worcester, U.K. SO 882567
Alan J Holmes
In article <81b7cc$11a3...@news.wmc.ac.uk>,
Chris Snowdon <csno...@wmc.ac.uk> wrote:
>Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>>I, some time ago, had to take a fuel consumption test on
>>my Escort, the tester said he and collegues had carried
>>out a number of tests for various loads on cars.
>>His experience was that a set of headlights switched on
>>resulted in an increased consumption of 3 miles per gallon of fuel.
>>Around 10% on most family cars.
>If that is true then I find it astonishing. Surely the engine drives
>the alternator regardless of whether your lights are on or off, or am
Find a car, take it to you friendly local garage and ask for a
fuel consumption test, carry out the test for yourself adn come
back with the results.
Alan
Chris Snowdon
In article <4vvs6p$2...@nuntius.u-net.net>, j...@greenow.u-net.com says...
>Try it for youself: (I am assuming you have access to a car)
>
>Sit in the car with the engine idling - foot off the accelerator - and
>observe the rev counter or the engine note.
>
>Now switch on some electrical gadgetry; lights, heated rear window,
>etc.
>
>You should notice a slight drop in the engine speed due to the
>increased electrical load. QED
Just tried it in a Nissan Micra.....I have to say that I didn't notice a
change in engine note (no tacho). I *do* understand what you are saying
and I know you don't get ought for nought in this life, but I still find
it hard to believe that the difference is as much as 10% on fuel
consumption. This would seem to me to say that 10% of the engines power
is being used to drive the alternator (over and above the normal power
used to drive it without the lights on). That's a lot of extra torque.
I'm not saying it's wrong (I don't know and I admit that) but it does
seem to be a very high figure and certainly doesn't relate to my own
experience.
Even if it does increase my consumption by 10% I would still drive with
headlights on.....in any decision between damage to the environment and
personal survival I'm afraid I'll opt for the latter!
Regards
Chris Snowdon (csno...@wmc.ac.uk) DOD#1856
FJ1200/GS850G UKMC#NotMeGuv
Network Management Team, Wirral Met College - England
(-: The views expressed here are my own - not my employers :-)
Chris Snowdon
c...@aisb.ed.ac.uk (Chris Malcolm) wrote:
<snip>
>>Does
>>the torque needed to turn the alternator vary significantly as more
>>currrent is drawn ?
>Of course it does! That's where the current comes from!
OK - I'm no expert, merely a seeker for knowledge.
>The extra current
>requires more torque input to the alternator, which comes from the
>engine, plus an extra percentage for friction and heat, which in turn
>comes from the petrol, plus an extra percentage for friction and heat
>again. Since some of the current comes from the battery (e.g. when
>stopped at lights) and is put back again later by the alternator, you
>have to add an extra factor too for the battery efficiency.
>Lights don't come free.
OK - I undertand the principle of conservation of mass/energy, I'm not
quite that dumb. I *am* completely dumb on electric motors and
generators other than a high school knowledge of generating current by
moving an iron mass through a magnetic field, so I must admit to
knowing nothing about the relationship between torque and current in
an alternator (though clearly I would expect one to rise with the
other). The point I was trying to make was that surely most of the
energy lost may be because of the mechanical resistance of the
fan-belt/alternator assembly rather than the increased torque needed
to turn the alternator under load. Since the alternator is driven
anyway then most of the torque is expended regardless of whether light
are used.
You are saying that most of the energy is expended because of the
increased torque required to turn the alternator under load.
OK - I'll bow to your superior knowledge..I've learned something.
I still don't get a measurable difference in mpg when using lights on
the FJ...maybe this is because it draws less current that a car would.
C.
Chris Snowdon
Paul Abraham <pa...@ntms.bt.co.uk> wrote:
>Chris Snowdon wrote:
>> The alternator is turning regardless of whether you use it's
>> output so much of the energy is being used regardless of whether you
>> use your lights or not.....
>This is like saying that the engine is turning whether you are moving
>or not. In this case you use as much fuel stationary as you do climbing a
>steep hill at 50 (given the same revs I suppose).
Well....it is turning isn't it ? And are you not using much of the
energy from the petrol whether you are moving or not ? Clearly as you
rev the engine you will use more fuel so, to be an exact analogy, you
would have to compare idling with moving at the same revs. I don't
know what the difference would be - clearly there would be one - my
original point was to question a posting giving a figure for power
expended in the lighting system and assuming that this would all come
from extra fuel usage.
>No, to take more out you have to put more in; there's no such thing
>as a free lunch. Its true that the alternator is not 100%
>efficient and so you need some power simply to drive it (against friction
>in the bearings, switching in the regulator etc), but the power required
>for lights etc is over and above that.
That's the main point......what's the relationship between the torque
needed to turn it anyway and the increased torque under load ?
C.
John Wright
On 20 Aug 1996 13:36:31 +0100, Alan J Holmes wrote:
>I, some time ago, had to take a fuel consumption test on
>my Escort, the tester said he and collegues had carried
>out a number of tests for various loads on cars.
>
>His experience was that a set of headlights switched on
>resulted in an increased consumption of 3 miles per gallon of fuel.
>
>Around 10% on most family cars.
If a car is travelling at a constant speed of something like 60 mph, then
the power needed to keep it at this speed will be on the order of 10's of
kilowatts, the engine will turn out something like 30 - 70 kW depening on
the mass/drag/speed of the car. The use of headlights in addition will add
about 120 watts to this, or 0.12 kW This is about 0.2 % of the output of
the car. Assuming a reasonably linear relationship (over a small range)
betwen power output and fuel consumption, this would be the increase in
fuel consumption, not 10%, or 0.06 mpg.
--
John Wright
Time is an illusion, lunchtime doubly so - Ix (Ford Prefect)
Fingerprint = D3 80 D9 38 F8 C9 D9 86 6B F1 DC F5 56 DF BC 82
** Boycott the Observer **
Steve Hunt
csno...@wmc.ac.uk (Chris Snowdon) writes:
> Just tried it in a Nissan Micra.....I have to say that I didn't notice a
> change in engine note (no tacho).
Try lots of heavy loads at once (heated rear window is good). Try it
with an old car. Modern engine management systems monitor the idle
speed and adjust it to compensate for loading.
-- Steve
--
Steve Hunt Persimmon IT, Inc. Cambridge, UK
http://www.persimmon.com/ steve...@persimmon.com
Normal disclaimers apply. E&OE, IMHO, AFAIK, ISTR, YMMV, ono. Etc
Chris Snowdon
In article <322584aa....@news.rl.ac.uk>, j...@isise.rl.ac.uk says...
>If a car is travelling at a constant speed of something like 60 mph, then
>the power needed to keep it at this speed will be on the order of 10's of
>kilowatts, the engine will turn out something like 30 - 70 kW depening on
>the mass/drag/speed of the car. The use of headlights in addition will add
>about 120 watts to this, or 0.12 kW This is about 0.2 % of the output of
>the car. Assuming a reasonably linear relationship (over a small range)
>betwen power output and fuel consumption, this would be the increase in
>fuel consumption, not 10%, or 0.06 mpg.
This sounds a bit more like it. 10% did seem to be a ridiculous figure.
I always accepted that lights do have an effect but questioned the figure of
10% (3-5mpg) on a typical car. That figure just 'feels' wrong when you
compare the power needed to drive the vehicle and the power needed to turn
the alternator.
Incidentally I posted a query on uk.rec.motorcycles on this subject and the
answer that makes the most sense up to know seems to show that a typical
bike uses up to 1% of power on the lights.....for a typical bike that would
be an mpg difference of about 0.5-0.8 mpg. That figure makes the fuel
factor totally irrelevant - like the original poster said you could loose
more than that with incorrectly inflated tyres......and fits in with my own
observations.
--
Chris Snowdon
Steve Hunt <ste...@dione.persimmon.co.uk> wrote:
>Try lots of heavy loads at once (heated rear window is good). Try it
>with an old car. Modern engine management systems monitor the idle
>speed and adjust it to compensate for loading.
Well, I could I suppose but I'm not sure how useful it would be in
determining the extra mpg caused by lights. It would, no doubt,
illustrate that the alternator does load the engine as more power is
drawn. I accept this. My point was really to ask what this would do
to mpg with just lights on. Alan H. claims he was told it would be
about 10%......that seems to me to be very high and counter-intuitive.
I'm not saying it's wrong (yet) because I'm still following the debate
with interest. I'm merely questioning the figure and trying to follow
the arguments of people far more informed than myself. I'm just about
managing at the moment :-)
Regards
Chris.
Alan J Holmes
In article <1996Aug27.1...@ucl.ac.uk>,
Martin Gilbert <m.gi...@ucl.ac.uk> wrote:
>csno...@wmc.ac.uk (Chris Snowdon) wrote:
>>Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>>>His experience was that a set of headlights switched on
>>>resulted in an increased consumption of 3 miles per gallon of fuel.
>>>Around 10% on most family cars.
>>If that is true then I find it astonishing. Surely the engine drives
>>the alternator regardless of whether your lights are on or off, or am
>>I missing something here ?
>[snip discussion over the likelihood of this figure]
>>Can anyone clarify this please ???????
>Yes: Alan's talking crap. Again.
Seems that others have proved that is not so!
But to briefly return to the original article where the writer
claimed that it was safer to drive with headlights on.
If you are unable to see an object about 5 feet wide and 5 feet
high without it having two great big lights on, should you not
consider giving up driving until your eyesight improves.
If you are unable to see something that big, what chance does a
child about 9 inches wide and 2.5 feet high stand?
Or is it that the headlights are suppose to intimidate the
pedestrian?
Alan
Alan J Holmes
In article <81c7cc$c333...@news.wmc.ac.uk>,
Chris Snowdon <csno...@wmc.ac.uk> wrote:
>Even if it does increase my consumption by 10% I would still drive with
>headlights on.....in any decision between damage to the environment and
>personal survival I'm afraid I'll opt for the latter!
I'm getting confused, and that's an easy thing to do!(:-)
I was under the impression that you were a confirmed
motorcyclist.
The figures I was given applied to cars.
Alan
Alan J Holmes
In article <322584aa....@news.rl.ac.uk>,
>>I, some time ago, had to take a fuel consumption test on
>>my Escort, the tester said he and collegues had carried
>>out a number of tests for various loads on cars.
>>His experience was that a set of headlights switched on
>>resulted in an increased consumption of 3 miles per gallon of fuel.
>>Around 10% on most family cars.
>If a car is travelling at a constant speed of something like 60 mph, then
>the power needed to keep it at this speed will be on the order of 10's of
>kilowatts, the engine will turn out something like 30 - 70 kW depening on
>the mass/drag/speed of the car. The use of headlights in addition will add
>about 120 watts to this, or 0.12 kW This is about 0.2 % of the output of
>the car. Assuming a reasonably linear relationship (over a small range)
>betwen power output and fuel consumption, this would be the increase in
>fuel consumption, not 10%, or 0.06 mpg.
I would hate to think that it required 30 kW to keep my car
running at 60 mph, I cant' help feeling you have overstated the
case somewhat.
But:-
I have quoted figures given to me by a man who spends his
working days testing fuel consumption on cars, I have no reason to
disbelieve him.
Alan
Andrew Willoughby
In article: <81e7cc$cd36...@news.wmc.ac.uk> csno...@wmc.ac.uk
(Chris Snowdon) writes:
> mpg difference of about 0.5-0.8 mpg. That figure makes the fuel
> factor totally irrelevant
I don't agree. Even 0.5 mpg is relevant because there are so many
cars.
Maybe motorbikes should drive with lights, but cars? No, lights are
for when it's dark. Switch 'em off and save fuel.
If you want to be more clearly seen why buy a car which is the same
colour as the road? I chose a white car and keep lights for when it's
dark.
--
Andrew
Slow down, relax, enjoy life!
No, not *that* slow, the legal limit will do nicely thanks!
Chris Snowdon
Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>Find a car, take it to you friendly local garage and ask for a
>fuel consumption test, carry out the test for yourself adn come
>back with the results.
OK Alan, I did just that.
I borrowed my mum's Micra this week for a day. My methodology is a
bit imprecise but it should serve to illustrate the point.
I topped the tank off and went for a run (no lights) from my house to
work (about 25 miles, part m/way, part 30mph and part 50-60mph). On
arrival I topped up again and arrived at an mpg of 49.58.
On the return journey I used dipped headlights.
The mpg figure was 49.14.
No OK, I accept that there were other variables - traffic, wind etc
etc - but I think this serves to illustrate that 10% is *way* over the
top.
C.
norma...@ukonline.co.uk
Dark - NO!
When visibility is reduced - YES!!
Think safety, then economy.
Norman Hart DoT ADI (XL School of Motoring)
PS. Due to finances, we all can't choose the colour of
the car we want!
Chris Snowdon
I think I've got to grips with this now. Thanks to those who took the
time to patiently explain the flaws in my reasoning - it's
appreciated.
After a bit of research and some field-work I've now arrived at the
following:-
1) A limited field-test indicated that the result for a Nissan Micra
was approximately 0.5mpg in 50 - about 1%.
2) The best theoretical position I can arrive at is (and thanks to
those whose brains I've picked) :-
I hp is about 750 watts (746 I think).
A car draws about 100-200 watts when headlights are used.
Generator/alternator efficiency is around 70-80% so let's be generous
and say a full half-horsepower is needed.
This would mean that a load of 50hp on the engine would result in 1%
powering the lights.
Obviously it depends on how you drive/ride as to the exact percentage
of your mpg being used on the lights but it seems to met that the
figure is in the region of 1%, not 10%.
My original reason for getting involved was that, as a biker, I ride
with lights all the time. I was concerned, therefore, by claims of
10% mpg difference.
As it happens I needent have worried. My FJ develops a maximum 120hp
(at the crank) and the lights require less than 100 watts in total.
Alllowing for alternator efficiency of 70% this means I use (hang
on...calculator needed) - about 0.2hp.
Even though I don't ride flat out all the time (can't afford the fines
:-) this still means that the difference is negligable (which also
fits in with my own observations).
Now I accept that this is pretty rough and ready reckoning....to be
more precise I suppose we should go much deeper into it and start
figuring calorific values of petrol, engine efficiency etc etc. I'm
not too concerned with arriving at an exact figure though - it's
enough to know that it is pretty minor....less than 1mpg...
Anyway, that's what I now believe. Anyone knowing better is welcome
to blow me away....
Regards
Chris.
Chris Snowdon
Andrew Willoughby <And...@willouby.demon.co.uk> wrote:
>I don't agree. Even 0.5 mpg is relevant because there are so many
>cars.
Bear in mind that the original argument was about side lights which
draw much less than even this figure.
>Maybe motorbikes should drive with lights, but cars? No, lights are
>for when it's dark. Switch 'em off and save fuel.
Well....I have no stong views on cars driving with lights because I
look out carefully for all vehicles (bikers have to).
>If you want to be more clearly seen why buy a car which is the same
>colour as the road? I chose a white car and keep lights for when it's
>dark.
There are problems with white cars. I remember in the winter of 1985
when there was a lot of snow on the ground. I set off for work in my
wife's metro but only got a few hundred yards before the windscreen
completely fogged (I cleaned it before setting off). The sun was low
in the sky and, to be honest, I could see almost nothing.
I slowed down in order to pull in and clear the screen. All of a
sudden CRASH. I ran into the back of a white escort that had stopped
in the middle of the road for the same reason (fogged windscreen).
OK - totally my fauly, no argument there, but I probably would have
seen a red or black car....
C.
Chris Snowdon
>I was under the impression that you were a confirmed
>motorcyclist.
I am.
>The figures I was given applied to cars.
Yes I know, but my mpg figures are similar to an average family car
and, although I use less juice for lights, it still would have been a
hefty drain based on 10% for cars....I'm glad I've managed to prove to
myself that isn't the case. Don't misunderstand me - I still would
drive with lights on, but it would have taken a slight edge of my
smile of enjoyment when riding.....
C.
Simon Culverhouse
Alan J Holmes <Alan....@brunel.ac.uk> wrote in article
<506n3g$i...@loki.brunel.ac.uk>...
> In article <1996Aug27.1...@ucl.ac.uk>,
> Martin Gilbert <m.gi...@ucl.ac.uk> wrote:
> >csno...@wmc.ac.uk (Chris Snowdon) wrote:
>
> >>>resulted in an increased consumption of 3 miles per gallon of fuel.
>
> >>>Around 10% on most family cars.
>
> >>the alternator regardless of whether your lights are on or off, or am
> >>I missing something here ?
>
> >[snip discussion over the likelihood of this figure]
>
> >>Can anyone clarify this please ???????
>
> >Yes: Alan's talking crap. Again.
>
> Seems that others have proved that is not so!
>
> But to briefly return to the original article where the writer
> claimed that it was safer to drive with headlights on.
>
> If you are unable to see an object about 5 feet wide and 5 feet
> high without it having two great big lights on, should you not
> consider giving up driving until your eyesight improves.
>
> If you are unable to see something that big, what chance does a
> child about 9 inches wide and 2.5 feet high stand?
>
> Or is it that the headlights are suppose to intimidate the
> pedestrian?
>
> Alan
>
>
through Prestwood (Bucks), where most vehicles did not have their lights
on. As I entered a wooded area, it darkened, and drivers still did not use
lights. There were dark cars, driving through dark woods, on a dull
morning !! They did not give a damn about other road users (INCLUDING
PEDESTRIANS) seeing them. They themselves could see the road, and they're
all right Jack ! Strangely enough, since I have been driving with dim-dip
(not full dipped beam) light on during the day, less people seem to pull
out in front of me when it is unsafe to do so. More importantly, the close
shaves I have had on m-ways and dual c-ways with people changing lanes in
front of me when I was closing at a far greater speed in the next lane have
ended. After I was nearly killed on the A5 passed Milton Keynes when I was
traveling about 70-80mph (with four cars behind) when some fool in a Golf
decided to move into my lane when he was doing about 50mph, I swore that I
would always use dim-dipped lights. Not only was I nearly killed, but the
car behind me would also have been involved. Needless to say that I was
not the only car to blow my horn at the Golf. Now he may not have seen me
because he never looked, but on the other hand he may have just missed me
(although I have a white car). SAFETY FIRST !!!! 1.5 tonnes of metal (and
more) can do more damage than a hand gun, yet no-one is worried about
people passing a test at 17 and then never needing to sit another test.
Too many people do not treat vehicles with the respect they deserve (an I'm
talking about the nut behind the wheel here, not innocent pedestrians).
Having visited Sweden and spoken to some of my colleagues there, and with
my brother having worked at Volvo in Goteborg, I have made an educated
decision based upon the facts I have obtained from these people to use
day-running lights. When new information comes to light which gives me
good reason not to use day-running lights I will. After all, it is
interesting to notice that the UK enforced dim-dip as a minimum until the
European government put their oar in. Also, it is illegal to use side
light in Germany when the car is in motion.
Simon.
--
Simon Culverhouse
simon.cu...@dial.pipex.com
Chris Snowdon
In article <506n3g$i...@loki.brunel.ac.uk>, Alan....@brunel.ac.uk
says...
>But to briefly return to the original article where the writer
>claimed that it was safer to drive with headlights on.
>
>If you are unable to see an object about 5 feet wide and 5 feet
>high without it having two great big lights on, should you not
>consider giving up driving until your eyesight improves.
All I can say is that there are a lot of people who fall into that
category....even more who don't notice a large motorbike (mostly white).
>If you are unable to see something that big, what chance does a
>child about 9 inches wide and 2.5 feet high stand?
Or a bike/motorbike a couple of feet wide.....
>Or is it that the headlights are suppose to intimidate the
>pedestrian?
Not at all. Ask any biker who does a lot of mileage. The chances are
they ride with lights on. It *does* make you more visible. The argument
about blinding other drivers cuts no ice with me....I don't think it does
dazzle them (my lights are set correctly, and even if it did dazzle the
occasional driver I consider it to be a risk worth taking. I find that
if I turn my lights off I suddenly become invisible to some drivers....
OK - it may be different for cars but I would certainly advise any rider
to use dipped lights at *all* times.....
Chris.
Martin Gilbert
Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>Martin Gilbert <m.gi...@ucl.ac.uk> wrote:
>>csno...@wmc.ac.uk (Chris Snowdon) wrote:
>>>Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>>>>His experience was that a set of headlights switched on
>>>>resulted in an increased consumption of 3 miles per gallon of fuel.
>>>>Around 10% on most family cars.
>>>If that is true then I find it astonishing. [snip discussion over the
>>> likelihood of this figure] Can anyone clarify this please ????
>>Yes: Alan's talking crap. Again.
>Seems that others have proved that is not so!
Well, I've yet to see confirmation of the 10% figure? I don't doubt
headlights take *some* power, but all I've seen on this thread is
glorified arm-waving as to the figures...
>But to briefly return to the original article where the writer
>claimed that it was safer to drive with headlights on.
>If you are unable to see an object about 5 feet wide and 5 feet
>high without it having two great big lights on, should you not
>consider giving up driving until your eyesight improves.
>If you are unable to see something that big, what chance does a
>child about 9 inches wide and 2.5 feet high stand?
>Or is it that the headlights are suppose to intimidate the
>pedestrian?
Alan, stop talking sense. You're frightening me.
Martin Gilbert
Chris Snowdon
Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>I would hate to think that it required 30 kW to keep my car
>running at 60 mph, I cant' help feeling you have overstated the
>case somewhat.
Well....30kW equates to about 40hp....it's not *that* overstated.
>But:-
>I have quoted figures given to me by a man who spends his
>working days testing fuel consumption on cars, I have no reason to
>disbelieve him.
No, but I reckon the only explanation for his 10% figure is that the
car was idling whilst the test was conducted. If the test were
carried out in normal driving conditions I don't see how he could
possibly arrive at such a figure unless there was a serious fault
affecting the car.
C.
Chris Malcolm
In article <9a7cc$1228...@news.wmc.ac.uk> csno...@wmc.ac.uk (Chris Snowdon) writes:
>Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>>I would hate to think that it required 30 kW to keep my car
>>running at 60 mph, I cant' help feeling you have overstated the
>>case somewhat.
>Well....30kW equates to about 40hp....it's not *that* overstated.
I'd be surprised if it took more than 15hp (11kW) to run a car at 60mph.
>>I have quoted figures given to me by a man who spends his
>>working days testing fuel consumption on cars, I have no reason to
>>disbelieve him.
>No, but I reckon the only explanation for his 10% figure is that the
>car was idling whilst the test was conducted.
Or possibly trundling along at 30mph?
Chris Snowdon
c...@aisb.ed.ac.uk (Chris Malcolm) wrote:
>>>I would hate to think that it required 30 kW to keep my car
>>>running at 60 mph, I cant' help feeling you have overstated the
>>>case somewhat.
>>Well....30kW equates to about 40hp....it's not *that* overstated.
>I'd be surprised if it took more than 15hp (11kW) to run a car at 60mph.
Too many variables to generalise usefully....weight, wind, road
etc...I suppose it could be anywhere between 10 and 50hp.
>>>I have quoted figures given to me by a man who spends his
>>>working days testing fuel consumption on cars, I have no reason to
>>>disbelieve him.
>>No, but I reckon the only explanation for his 10% figure is that the
>>car was idling whilst the test was conducted.
>Or possibly trundling along at 30mph?
Hmm....lights take (say) 150W....divide by 750 = about 0.2hp
If the light take 10% then the car is using 2hp to travel at
30mph....I suppose it's possible but I don't reckon it's anywhere near
typical....
Chris.
Chris Snowdon
r...@maths.warwick.ac.uk (Mr R M Mantel) wrote:
>Considering that the 2CV is rated at 20kW and capable of attending 80
>mph, this is clearly overrated. Small motor bikes of 7kW (10-12hp)
>are just about able to reach 60 mph, so even a car with very fat tyres
>should not need more than 10kW to sustain running at 60 mph.
OK, I accept the figure for bikes (I've got one in that category) but
I reckon an Escort (the car in question) would need much more power
for the same speed (more weight, more air resistance etc). I guess
that 10kW is too little. Let's compromise and say 15kW for the Escort
to travel at 60mph. OK ?
At 15kW output ( assuming the lights draw about 150W) then a perfect
generator would be drawing 1%. I understand that generators are in
the region of 70% efficient so I stand by my original comment - 10% is
*way* to high...nearly an order of magnitude out in this case.....
BTW - I am *not* saying that Alan was talking crap (in this case
anyway)....I'm not expert enough to be definitive, I was merely
interested in the debate and have followed it very closely. The only
way I can see the 10% figure being accurate is at *very* low speed.
The problem is the number of variables and the less than scientific
way I have approached the problem.....the range of potential error is
large, but I don't reckon 10% is a 'fair' figure.
Chris.
Mr R M Mantel
>>>>> "Chris" == Chris Snowdon <csno...@wmc.ac.uk> writes:
Chris> Alan....@brunel.ac.uk (Alan J Holmes) wrote:
>> I would hate to think that it required 30 kW to keep my car
>> running at 60 mph, I cant' help feeling you have overstated the
>> case somewhat.
Chris> Well....30kW equates to about 40hp....it's not *that*
Chris> overstated.
Considering that the 2CV is rated at 20kW and capable of attending 80
mph, this is clearly overrated. Small motor bikes of 7kW (10-12hp)
are just about able to reach 60 mph, so even a car with very fat tyres
should not need more than 10kW to sustain running at 60 mph.
Rolf
--
Rolf Mantel, * ma...@csv.warwick.ac.uk @ ) _ _
Dept. of Mathematics, * r...@maths.warwick.ac.uk /\ * | |_| |
University of Warwick, * _`\ `_(== | |
Coventry CV4 7AL, England * ________________________(_)/_(_)______ | |
John Wright
On 10 Sep 1996 19:45:02 GMT, Chris Malcolm wrote:
>In article <9a7cc$1228...@news.wmc.ac.uk> csno...@wmc.ac.uk (Chris Snowdon) writes:
>
>>>I would hate to think that it required 30 kW to keep my car
>>>running at 60 mph, I cant' help feeling you have overstated the
>>>case somewhat.
>
>
>I'd be surprised if it took more than 15hp (11kW) to run a car at 60mph.
Very early 850cc mini's used to have a job getting much past 60 mph on 41
hp. Whilst minis have a relatively poor drag coefficient, their frontal
area is small compared to many modern cars.
John Wright
On 10 Sep 1996 22:20:24 +0100, Mr R M Mantel wrote:
>>>>>> "Chris" == Chris Snowdon <csno...@wmc.ac.uk> writes:
>
> >> I would hate to think that it required 30 kW to keep my car
> >> running at 60 mph, I cant' help feeling you have overstated the
> >> case somewhat.
>
> Chris> overstated.
>
>Considering that the 2CV is rated at 20kW and capable of attending 80
>mph, this is clearly overrated.
Downhill with the wind behind it perhaps - not many 2CVs overtake me on the
motorway :-)
>Small motor bikes of 7kW (10-12hp)
>are just about able to reach 60 mph, so even a car with very fat tyres
>should not need more than 10kW to sustain running at 60 mph.
Motorbikes are aerodynamically awful, but their frontal area is very small
- maybe an order of magnitude less than a car. Some racing cyclists can
get up to 60mph - but I wouldn't use their power output for comparison with
a car.
Andrew Henry
In article <32380eca....@news.rl.ac.uk>,
>
>Very early 850cc mini's used to have a job getting much past 60 mph on 41
>hp. Whilst minis have a relatively poor drag coefficient, their frontal
>area is small compared to many modern cars.
>
850cc Minis had a 33 Bhp engine if I remember correctly.
The A series 998cc engine was 40 bhp or so.
It takes a lot more power to accelerate to a given speed
than it does to maintain that speed. My first car was a tired
Mini 850 with an optimistic speedo (it read 20mph when it was
stationary). Even so, I timed it at a little over 70 mph on a
flat motorway.
--
Andrew Henry
ahe...@dircon.co.uk
Mr R M Mantel
>>>>> "John" == John Wright <j...@isise.rl.ac.uk> writes:
>> Considering that the 2CV is rated at 20kW and capable of
>> attending 80 mph, this is clearly overrated.
John> Downhill with the wind behind it perhaps - not many 2CVs
John> overtake me on the motorway :-)
My mum in Germany occasionally does runs on the motorway doing 60 km
(just under 40 miles) in half an hour. I have occasionally had the
speedometer show 140 km/h when alone. I assume that is a bit
optimistic but not too much. But the inferno inside the car makes sure
people don't want to drive faster than ca. 50 mph unless there's a
very good reason or they're deaf.
Chris Snowdon
ahe...@tdc.dircon.co.uk (Andrew Henry) wrote:
>It takes a lot more power to accelerate to a given speed
>than it does to maintain that speed. My first car was a tired
>Mini 850 with an optimistic speedo (it read 20mph when it was
>stationary). Even so, I timed it at a little over 70 mph on a
>flat motorway.
How did you do that ? Just interested......
Chris.
Alan J Holmes
In article <514gfu$8...@scotsman.ed.ac.uk>,
Chris Malcolm <c...@aisb.ed.ac.uk> wrote:
>In article <9a7cc$1228...@news.wmc.ac.uk> csno...@wmc.ac.uk (Chris Snowdon) writes:
>
>>>I would hate to think that it required 30 kW to keep my car
>>>running at 60 mph, I cant' help feeling you have overstated the
>>>case somewhat.
>
>
>I'd be surprised if it took more than 15hp (11kW) to run a car at 60mph.
>
>>>working days testing fuel consumption on cars, I have no reason to
>>>disbelieve him.
>
>>No, but I reckon the only explanation for his 10% figure is that the
>>car was idling whilst the test was conducted.
>
>Or possibly trundling along at 30mph?
it did at the 'government calculated figures' of maximun economy
at 55 mph.
Alan
Tom Wheeley
On Thursday, in article <842580...@llondel.demon.co.uk>
da...@llondel.demon.co.uk "David Hough" wrote:
> In article <32380eca....@news.rl.ac.uk>
> j...@isise.rl.ac.uk (John Wright) writes:
> >
> > Very early 850cc mini's used to have a job getting much past 60 mph on 41
> > hp. Whilst minis have a relatively poor drag coefficient, their frontal
> > area is small compared to many modern cars.
> >
> Wasn't the problem with the 850cc Mini that only about half the engine
> power was available for driving the wheels, having overcome friction
> losses, dynamo/alternator load, fan etc. This is why the 1000cc Mini was
> so much better, simply because the *available* power was nearly
> double....
Well friction is an important factor here, seeing as the power req'd to
maintain a speed is merely to overcome friction:
P=Fv
where P=Power, F=Friction, v=velocity.
Then there's acceleration, which is where most of the power is used;
consider that a 1 tonne car moving at 60mph (27m/s) has a kinetic energy
of over 350kJ, and that energy has to come from somewhere
.splitbung (pwei barmy army, essex paragraph) http://www.tsys.demon.co.uk
--
Peace is War,
Freedom is Slavery
Beer is NICE!!!!
[m...@coventry.ac.uk]
Andrew Henry
In article <9c7cc$17f1...@news.wmc.ac.uk>,
Hold a steady speed and time how long it takes to
get between the kilometre posts. These probably
aren't placed with a high degree of accuracy, but
I would expect the errors to balance themselves
out over a few miles. At 70 mph, it should take
32 seconds to travel 1km.
You can also measure your speed by the average speed of
drivers overtaking police cars, or by cruising past
active Gatsos :-)
--
Andrew Henry
ahe...@dircon.co.uk
Chris Snowdon
Alan....@brunel.ac.uk (Alan J Holmes) wrote:
<snip fair description of imprecise test>
I accept the criticism....fair enough it was not a very good test.
I'll try to arrange a better test next week and post the results...
Chris.
Gareth Rees
John Wright <j...@isise.rl.ac.uk> wrote:
> Some racing cyclists can get up to 60mph
This is false for unpaced upright cycles on flat surfaces, as the record
for 200m (flying start) is about 10 seconds, i.e. about 45mph. (For
comparison, the record for 4km (stationary start) is about 4 minutes,
i.e. about 37mph, and Chris Boardman's hour record of 56+km is about
35mph.)
Do you refer to motor-paced, downhill or recumbent cyclists?
--
Gareth Rees
Thomas Sippel - Dau
In article <323811c6....@news.rl.ac.uk>, j...@isise.rl.ac.uk (John Wright) writes:
- Motorbikes are aerodynamically awful, but their frontal area is very small
- - maybe an order of magnitude less than a car. Some racing cyclists can
- get up to 60mph - but I wouldn't use their power output for comparison with
- a car.
Sorry ?
Motorbike - 60 cm wide, 1.5 m high, not exactly square, so allow 30% for that.
0.6 * 1.5 * 0.7 * 1.25 (typical cw value) => 0.79 effective frontal area
Car - 1.7 m wide, 1.4 high, almost square, typical cw 0.3 (for current
style bulbous cars) to 0.35 ('50 to '80 designs)
=> 0.71 to 0.84 square meter effective area, so
*** more or less the same air resistance ***
Typically air resistance becomes dominant at 20 - 25 m/s, that is when
motorbike riders start ducking behind the shield and car drivers close
their windows, (around 80 km/h, 50 mph).
A cyclist with an appropriate gearing can reach 75-80 m/s (250-300 km/h,
160-200 mph) *** in the wind shadow ***
Thomas
--
*** Why not use metric units and get things right first time, every time.
* email: cma...@ic.ac.uk (Thomas Sippel - Dau)
* voice: +44 171 594 6904 (day), +44 171 594 6958 (fax), +44 171 385 6540
* snail: ICSTM, Computing Services, Kensington SW7 2BX, Great Britain
Alan J Holmes
In article <yxsenjtxl...@stint.cl.cam.ac.uk>,
Gareth Rees <gd...@cl.cam.ac.uk> wrote:
>John Wright <j...@isise.rl.ac.uk> wrote:
>> Some racing cyclists can get up to 60mph
>This is false for unpaced upright cycles on flat surfaces, as the record
>for 200m (flying start) is about 10 seconds, i.e. about 45mph. (For
>comparison, the record for 4km (stationary start) is about 4 minutes,
>i.e. about 37mph, and Chris Boardman's hour record of 56+km is about
>35mph.)
I'm very sceptical about the speeds so called racing cyclists
achieve.
I once cycled from Ealing to Stow on the Wold, a distance of 84
miles, the journey took 2 hours 50 minutes, I was riding a bicycle
equiped for a fortnights holiday, clothing, food, water bottles,
primus stoves, parrafin, meths and etc.
The bike was a standard roadster type, the average speed was about
29 miles per hour, remember that much of it was uphill through the Chilterns
and Cotswolds, I calculate that at times, I had to be travelling at about
45 - 50 miles per hour, and that on a _very_ heavy bike.
Alan
Andrew Henry
In article <52drvm$t...@ccsp-24.brunel.ac.uk>,
Alan J Holmes <Alan....@brunel.ac.uk> wrote:
>I'm very sceptical about the speeds so called racing cyclists
>achieve.
>I once cycled from Ealing to Stow on the Wold, a distance of 84
>miles, the journey took 2 hours 50 minutes, I was riding a bicycle
>equiped for a fortnights holiday, clothing, food, water bottles,
>primus stoves, parrafin, meths and etc.
>The bike was a standard roadster type, the average speed was about
>29 miles per hour, remember that much of it was uphill through the Chilterns
>and Cotswolds, I calculate that at times, I had to be travelling at about
>45 - 50 miles per hour, and that on a _very_ heavy bike.
How did you measure the distance and how did you measure the
time ? How fit were you at the time ? Were you riding in
a group or on your own ?
--
Andrew Henry
ahe...@dircon.co.uk
Charlie Wartnaby
>I'm very sceptical about the speeds so called racing cyclists
>achieve.
>
>I once cycled from Ealing to Stow on the Wold, a distance of 84
>miles, the journey took 2 hours 50 minutes, I was riding a bicycle
>equiped for a fortnights holiday, clothing, food, water bottles,
>primus stoves, parrafin, meths and etc.
>
>The bike was a standard roadster type, the average speed was about
>29 miles per hour, remember that much of it was uphill through the Chilterns
>and Cotswolds, I calculate that at times, I had to be travelling at about
>45 - 50 miles per hour, and that on a _very_ heavy bike.
>
>
Was there an absolutely stonking following gale, or did you simply pass
up your chance for olympic glory? Perhaps a guy rope on your tent became
entangled with part of a passing motor vehicle? Were this not way back
in the past, one might wonder if you had your cycle computer set to km
instead of miles -- though even 18mph is very respectable for the load,
bicycle and terrain you describe.
--
Charlie Wartnaby, Cambridge. cha...@wartnaby.demon.co.uk
ralph moorhouse
On 26 Sep 1996, Alan J Holmes wrote:
> I once cycled from Ealing to Stow on the Wold, a distance of 84
> miles, the journey took 2 hours 50 minutes, I was riding a bicycle
> equiped for a fortnights holiday, clothing, food, water bottles,
> primus stoves, parrafin, meths and etc.
>
> The bike was a standard roadster type, the average speed was about
> 29 miles per hour, remember that much of it was uphill through the Chilterns
> and Cotswolds, I calculate that at times, I had to be travelling at about
> 45 - 50 miles per hour, and that on a _very_ heavy bike.
You have *got* to be joking. I have just checked the National rankings
for time trial cyclists from last week's Cycling Weekly.
One Andy Wilkinson, who recently rode over 300 miles (just)in 12 hours,
took 3 hrs 27 minutes and 39 seconds to ride 100 miles, at an average
speed of more or less 29 mph dead. This on a specific time trial bike,
ridden by one of the best time triallists in the country.
Your average speed, across the Cotswolds, with camping gear, on a
roadster (this just gets better and better!) was apparently 29.6 mph.
r.
ralph moorhouse, institute of education, university of hull
tel: +44 (0)1482 465031 fax: +44 (0)1482 466133
www:http://www.hull.ac.uk/php/edsrm
Alan J Holmes
In article <52o9e8$g...@tdc.dircon.co.uk>,
>>I'm very sceptical about the speeds so called racing cyclists
>>achieve.
>>I once cycled from Ealing to Stow on the Wold, a distance of 84
>>miles, the journey took 2 hours 50 minutes, I was riding a bicycle
>>equiped for a fortnights holiday, clothing, food, water bottles,
>>primus stoves, parrafin, meths and etc.
>>The bike was a standard roadster type, the average speed was about
>>29 miles per hour, remember that much of it was uphill through the Chilterns
>>and Cotswolds, I calculate that at times, I had to be travelling at about
>>45 - 50 miles per hour, and that on a _very_ heavy bike.
>How did you measure the distance and how did you measure the
>time ? How fit were you at the time ? Were you riding in
>a group or on your own ?
The distance was measured by a trip odometer on the front wheel,
the time was measured by clock. I left home at 2.00 pm expecting
to arrive at the Hostel at about 6.00 pm, when I got to the
Hostel it was closed, i asked someone sitting outside what the
problem was, and the answer was that the Hostel was not yet open,
it was 4.50 pm.
Alan
Alan J Holmes
In article <52of7b$6...@loki.brunel.ac.uk>,
Sorry, forgot to add, i was fairly fit, having been cycling
everywhere for about 6 years, and riding on my own.
But I should add, I have never been interested in trying to beat
the clock, I just rode as the fancy took me. Road racing was not
my scene.
Alan
Andrew Henry
In article <i6K5SCAd...@wartnaby.demon.co.uk>,
Charlie Wartnaby <cha...@wartnaby.demon.co.uk> wrote:
>In article <52drvm$t...@ccsp-24.brunel.ac.uk>, Alan J Holmes
>>I'm very sceptical about the speeds so called racing cyclists
>>achieve.
>>I once cycled from Ealing to Stow on the Wold, a distance of 84
>>miles, the journey took 2 hours 50 minutes, I was riding a bicycle
>>equiped for a fortnights holiday, clothing, food, water bottles,
>>primus stoves, parrafin, meths and etc.
>>The bike was a standard roadster type, the average speed was about
>>29 miles per hour, remember that much of it was uphill through the Chilterns
>>and Cotswolds, I calculate that at times, I had to be travelling at about
>>45 - 50 miles per hour, and that on a _very_ heavy bike.
>Was there an absolutely stonking following gale, or did you simply pass
>up your chance for olympic glory? Perhaps a guy rope on your tent became
>entangled with part of a passing motor vehicle? Were this not way back
>in the past, one might wonder if you had your cycle computer set to km
>instead of miles -- though even 18mph is very respectable for the load,
>bicycle and terrain you describe.
84 miles in 2 hours 50 minutes is an average of 47.70 kph.
That would have been fast enough to have held the world hour
record until 1967.
--
Andrew Henry
ahe...@dircon.co.uk
Alan J Holmes
In article <i6K5SCAd...@wartnaby.demon.co.uk>,
Charlie Wartnaby <cha...@wartnaby.demon.co.uk> wrote:
>In article <52drvm$t...@ccsp-24.brunel.ac.uk>, Alan J Holmes
><Alan....@brunel.ac.uk> writes
>>I'm very sceptical about the speeds so called racing cyclists
>>achieve.
>>I once cycled from Ealing to Stow on the Wold, a distance of 84
>>miles, the journey took 2 hours 50 minutes, I was riding a bicycle
>>equiped for a fortnights holiday, clothing, food, water bottles,
>>primus stoves, parrafin, meths and etc.
>>The bike was a standard roadster type, the average speed was about
>>29 miles per hour, remember that much of it was uphill through the Chilterns
>>and Cotswolds, I calculate that at times, I had to be travelling at about
>>45 - 50 miles per hour, and that on a _very_ heavy bike.
>Was there an absolutely stonking following gale, or did you simply pass
>up your chance for olympic glory?
Neither, as I remember the weather was good. I'm not in the
least interested in racing, I just kept cycling.
> Perhaps a guy rope on your tent became
>entangled with part of a passing motor vehicle?
Those were the days when passing motor vehicles were few and far
between.
>Were this not way back
>in the past, one might wonder if you had your cycle computer set to km
>instead of miles -- though even 18mph is very respectable for the load,
>bicycle and terrain you describe.
Don't understand this comment.
Alan
Alan J Holmes
In article <52qkls$7...@tdc.dircon.co.uk>,
Andrew Henry <ahe...@tdc.dircon.co.uk> wrote:
>In article <i6K5SCAd...@wartnaby.demon.co.uk>,
>Charlie Wartnaby <cha...@wartnaby.demon.co.uk> wrote:
>>In article <52drvm$t...@ccsp-24.brunel.ac.uk>, Alan J Holmes
>><Alan....@brunel.ac.uk> writes
>>>I'm very sceptical about the speeds so called racing cyclists
>>>achieve.
>84 miles in 2 hours 50 minutes is an average of 47.70 kph.
>That would have been fast enough to have held the world hour
>record until 1967.
Which is exactly my point.
Alan
K A Goatman
>> I once cycled from Ealing to Stow on the Wold, a distance of 84
>> miles, the journey took 2 hours 50 minutes, I was riding a bicycle
>> equiped for a fortnights holiday, clothing, food, water bottles,
>> primus stoves, parrafin, meths and etc.
>>
>> The bike was a standard roadster type, the average speed was about
>> 29 miles per hour, remember that much of it was uphill through the Chilterns
>> and Cotswolds, I calculate that at times, I had to be travelling at about
>> 45 - 50 miles per hour, and that on a _very_ heavy bike.
>You have *got* to be joking. I have just checked the National rankings
Either he's joking or the reason the bike was so _very_ heavy was the
addition of an engine.
Keith
--
Keith A Goatman Medical Physics and Clinical Eng.
Royal Hallamshire Hospital
E-mail : K.A.G...@Sheffield.ac.uk SHEFFIELD, U.K.
Nick Maclaren
In article <52uakr$e...@bignews.shef.ac.uk>,
K A Goatman <mp94...@stoat.shef.ac.uk> wrote:
>ralph moorhouse (ed...@humus2.ucc.hull.ac.uk) wrote:
>>On 26 Sep 1996, Alan J Holmes wrote:
>
>>> I once cycled from Ealing to Stow on the Wold, a distance of 84
>>> miles, the journey took 2 hours 50 minutes, I was riding a bicycle
>>> equiped for a fortnights holiday, clothing, food, water bottles,
>>> primus stoves, parrafin, meths and etc.
>>>
>>> The bike was a standard roadster type, the average speed was about
>>> 29 miles per hour, remember that much of it was uphill through the Chilterns
>>> and Cotswolds, I calculate that at times, I had to be travelling at about
>>> 45 - 50 miles per hour, and that on a _very_ heavy bike.
>
>>You have *got* to be joking. I have just checked the National rankings
>
>Either he's joking or the reason the bike was so _very_ heavy was the
>addition of an engine.
No, no. That is quite unnecessary. A sizable spinnaker and a following
wind (Beaufort 11 or 12, of course) is all that is needed :-)
Nick Maclaren,
University of Cambridge Computer Laboratory,
New Museums Site, Pembroke Street, Cambridge CB2 3QG, England.
Email: nm...@cam.ac.uk
Tel.: +44 1223 334761 Fax: +44 1223 334679
J W B Greenwood
In article <Pine.SOL.3.91.96093...@humus2.ucc.hull.ac.uk>,
ralph moorhouse <URL:mailto:ed...@humus2.ucc.hull.ac.uk> wrote:
>
> On 26 Sep 1996, Alan J Holmes wrote:
>
> > I once cycled from Ealing to Stow on the Wold, a distance of 84
> > miles, the journey took 2 hours 50 minutes, I was riding a bicycle
> > equiped for a fortnights holiday, clothing, food, water bottles,
> > primus stoves, parrafin, meths and etc.
> >
> > The bike was a standard roadster type, the average speed was about
> > 29 miles per hour, remember that much of it was uphill through the Chilterns
> > and Cotswolds, I calculate that at times, I had to be travelling at about
> > 45 - 50 miles per hour, and that on a _very_ heavy bike.
>
> You have *got* to be joking. I have just checked the National rankings
>
> One Andy Wilkinson, who recently rode over 300 miles (just)in 12 hours,
> took 3 hrs 27 minutes and 39 seconds to ride 100 miles, at an average
> speed of more or less 29 mph dead. This on a specific time trial bike,
> ridden by one of the best time triallists in the country.
>
> Your average speed, across the Cotswolds, with camping gear, on a
> roadster (this just gets better and better!) was apparently 29.6 mph.
>
I've just been reading a report in the paper that people, 20 years
ago, were five time fitter than they are now. Given that, less traffic
on the road and a following wind (-up), why not ???
Tim Williams
>> > I once cycled from Ealing to Stow on the Wold, a distance of 84
>> > miles, the journey took 2 hours 50 minutes,
...etc
>>
>> You have *got* to be joking. I have just checked the National rankings
>> for time trial cyclists from last week's Cycling Weekly.
>>
>> One Andy Wilkinson, who recently rode over 300 miles (just)in 12 hours,
>> took 3 hrs 27 minutes and 39 seconds to ride 100 miles, at an average
>> speed of more or less 29 mph dead.
>>
...etc
>
>I've just been reading a report in the paper that people, 20 years
>ago, were five time fitter than they are now. Given that, less traffic
>on the road and a following wind (-up), why not ???
>
Five times fitter than Andy Wilkinson? I think not. Five times fitter than
FRED Wilkinson (32) of 72 The Crescent, Suburbia who goes for occasional long
walks but only when he's late for work and has to park the car at the far side
of the car park.
Fred's grandfather might have set off on his bike to Stow but Fred couldn't do
it even if he had a tailwind and it was downhill all the way.
Tim.
_______
/ _____ \
/ / | | \ \
| (_______) |
|\-( )-( )- /
e=oOOo=oOOo=a
0\\__/@\__/ 0
J \ @ ( J
| % \
| |0\ \
| |0 \ \
| |0 (@@@)
| |0
( )0
(@@@)0
0
0
Alan J Holmes
In article <Pine.SOL.3.91.96093...@humus2.ucc.hull.ac.uk>,
>> I once cycled from Ealing to Stow on the Wold, a distance of 84
>> miles, the journey took 2 hours 50 minutes, I was riding a bicycle
>> equiped for a fortnights holiday, clothing, food, water bottles,
>> primus stoves, parrafin, meths and etc.
>> The bike was a standard roadster type, the average speed was about
>> 29 miles per hour, remember that much of it was uphill through the Chilterns
>> and Cotswolds, I calculate that at times, I had to be travelling at about
>> 45 - 50 miles per hour, and that on a _very_ heavy bike.
>You have *got* to be joking. I have just checked the National rankings
>for time trial cyclists from last week's Cycling Weekly.
>One Andy Wilkinson, who recently rode over 300 miles (just)in 12 hours,
>took 3 hrs 27 minutes and 39 seconds to ride 100 miles, at an average
>speed of more or less 29 mph dead. This on a specific time trial bike,
>ridden by one of the best time triallists in the country.
>Your average speed, across the Cotswolds, with camping gear, on a
>roadster (this just gets better and better!) was apparently 29.6 mph.
Yes, so what's your point?
On another occasion I was cycling along, going home from work,
taking things easy, when I became aware of a car following, he
stuck behind me for about five minutes, and I was getting a bit
agitated by him, when he pulled alongside, wound down the
window, shouted to me that I was doing 30 mph, then drove off.
Now it could have been that his speedometer was a little
generous, but my point is that I was making no particular effort
to cycle fast, I still have my doubts about racing cyclist and so
called time trials.
Alan
Alan J Holmes
In article <5307th$5...@gatekeeper.origin-at.co.uk>,
Tim Williams <twil...@origin-at.co.uk> wrote:
>>> > I once cycled from Ealing to Stow on the Wold, a distance of 84
>>> > miles, the journey took 2 hours 50 minutes,
> ...etc
>>> You have *got* to be joking. I have just checked the National rankings
>>> for time trial cyclists from last week's Cycling Weekly.
>>> One Andy Wilkinson, who recently rode over 300 miles (just)in 12 hours,
>>> took 3 hrs 27 minutes and 39 seconds to ride 100 miles, at an average
>>> speed of more or less 29 mph dead.
> ...etc
>>I've just been reading a report in the paper that people, 20 years
>>ago, were five time fitter than they are now. Given that, less traffic
>>on the road and a following wind (-up), why not ???
>Five times fitter than Andy Wilkinson? I think not. Five times fitter than
>FRED Wilkinson (32) of 72 The Crescent, Suburbia who goes for occasional long
>walks but only when he's late for work and has to park the car at the far side
>of the car park.
My point was not so much whether we were fitter at the time, but
more a question of equipment. The fad for racing cyclists is
that they _have_ to have bikes which a small child can lift with
their little finger, I happen to think that from my own experience
that is all wrong.
Alan
Dave Ewart
Alan J Holmes wrote:
> The distance was measured by a trip odometer on the front wheel,
> the time was measured by clock. I left home at 2.00 pm expecting
> to arrive at the Hostel at about 6.00 pm, when I got to the
> Hostel it was closed, i asked someone sitting outside what the
> problem was, and the answer was that the Hostel was not yet open,
> it was 4.50 pm.
SHERLOCK Holmes asks: "If you needed to ask someone the time, how can
you be so sure of the time at which you left?"
Dave.
--
Dave Ewart (Imperial Cancer Research Fund, Oxford)
ew...@icrf.icnet.uk
The ICRF WWW page is at http://www.icnet.uk/public.html
Alan J Holmes
In article <3254BB...@icrf.icnet.uk>,
Dave Ewart <ew...@icrf.icnet.uk> wrote:
>Alan J Holmes wrote:
>> The distance was measured by a trip odometer on the front wheel,
>> the time was measured by clock. I left home at 2.00 pm expecting
>> to arrive at the Hostel at about 6.00 pm, when I got to the
>> Hostel it was closed, i asked someone sitting outside what the
>> problem was, and the answer was that the Hostel was not yet open,
>> it was 4.50 pm.
>SHERLOCK Holmes asks: "If you needed to ask someone the time, how can
>you be so sure of the time at which you left?"
Cos I looked at the clock at home before I left, I wanted to
leave home at 2.00 pm and that is what I did, I did not at the
time wear a watch so I had to ask the time when I arrived at the
hostel and found it still shut.
Alan
Charlie Wartnaby
In article <52qrvp$l...@loki.brunel.ac.uk>, Alan J Holmes
<Alan....@brunel.ac.uk> writes
>In article <i6K5SCAd...@wartnaby.demon.co.uk>,
>Charlie Wartnaby <cha...@wartnaby.demon.co.uk> wrote:
>>in the past, one might wonder if you had your cycle computer set to km
>>instead of miles -- though even 18mph is very respectable for the load,
>>bicycle and terrain you describe.
>
>Don't understand this comment.
>
>Alan
I meant that if the distance were 84 km rather than 84 miles, your
average speed would be reduced by a factor of c. 1.609, bringing it
within the bounds of mortal achievement. Forget my proviso about when it
happened, for I expect that mechanical odometers were available in both
metric and imperial flavours then? (Especially with the French influence
in matters cycling.) And then as now, one has to make sure that these
devices are set up appropriately for the diameter of one's front wheel:
using an 18" wheel odometer with a 27" wheel bike would indeed give
flattering results.