Frame Fit

[Guy Gadboit]

Cross-posting or whatever from another forum here:

https://www.bikeforums.net/fitting-your-bike/1222465-moisture-s-unique-frame-fit.html

But I found this thread very interesting apropos comments made in the past by Nick Maclaren.

I don't claim to be a fit expert but this young-looking guy is going with very high seat, toes-down, and straight back.

Of course everyone is saying he's an idiot and should know better... But I feel there's a lot of fashion pretending to be pseudo-science in the subject of bike fit.

[Nick Maclaren]

In article <46a6ed18-2edf-4f49...@googlegroups.com>,

As you say. Sanity has prevailed in the tyre width issue, but I can
remember being abused either on this forum or the unmoderated one
for claiming that wider tyres had less rolling resistance on real
roads. I don't expect to live long enough to see sanity prevail on
either of these, but I might be surprised. I notice that the abuse
and pro-UCI-style propaganda hasn't changed.

I can add another disadvantage of that position to the one he mentioned
(aerodynamics) - it reduces how hard you can brake.

Either? Notice the dogma that the weight has to be equal on the two
wheels - as with cars, 60/40 is better in some ways than 50/50 and
worse in others.


Regards,
Nick Maclaren.

[Guy Gadboit]

[...]

> I can add another disadvantage of that position to the one he
> mentioned (aerodynamics) - it reduces how hard you can brake.

Because of weight distribution?

> Either? Notice the dogma that the weight has to be equal on the two
> wheels - as with cars, 60/40 is better in some ways than 50/50 and
> worse in others.

They're saying he'll get a sore butt. But many of us sit on our butts
practically all day with no issues. A comfortable seat is likely to be a
better solution than putting weight on your hands.

If designing a frame around this kind of fit it might make sense to have
longer chainstays and a reasonably short top tube. Then you could still
sit on the seat but the weight distribution between the wheels would be
a bit more even.

One thing I don't understand is the trend for really short chainstays on
"long low slack" MTBs. Often to the point where the seat-tube is bent
backwards almost over the back wheel. Sometimes they then make the
seat-tubes steeper to get the weight a little bit further forward. Maybe
it's just so they still fit in the box after they made the front of the
bike so long.

[Nick Maclaren]

In article <aa707a03-2be6-4e9e...@googlegroups.com>,

Guy Gadboit <benc....@googlemail.com> wrote:
>
>> I can add another disadvantage of that position to the one he
>> mentioned (aerodynamics) - it reduces how hard you can brake.
>
>Because of weight distribution?

How DID you guess? :-) That position can move the aggregate centre of
gravity from (say) 90 cm to 120 cm above the ground. Much better
visibility, but much easier to go over.

>> Either? Notice the dogma that the weight has to be equal on the two
>> wheels - as with cars, 60/40 is better in some ways than 50/50 and
>> worse in others.
>
>They're saying he'll get a sore butt. But many of us sit on our butts
>practically all day with no issues. A comfortable seat is likely to be a
>better solution than putting weight on your hands.

And, in that position, the requirement for a very narrow saddle is
essentially absent. Yes, especially for those of us who have trouble
putting weight on our hands.

>If designing a frame around this kind of fit it might make sense to have
>longer chainstays and a reasonably short top tube. Then you could still
>sit on the seat but the weight distribution between the wheels would be
>a bit more even.

If that's what you want, yes. But more weight on the rear improves
the grip on slippery stuff and improves the braking slightly. It's
not great up steep slopes, though, as you can fall off backwards :-)

>One thing I don't understand is the trend for really short chainstays on
>"long low slack" MTBs. Often to the point where the seat-tube is bent
>backwards almost over the back wheel. Sometimes they then make the
>seat-tubes steeper to get the weight a little bit further forward. Maybe
>it's just so they still fit in the box after they made the front of the
>bike so long.

I once rode a bicycle with a 60 degree frame angle - despite dogma,
it makes essentially damn-all difference to the handling. What DOES
make a difference is the steering tube angle, offset and all that,
but there's no reason the angles have to be the same.


Regards,
Nick Maclaren.

[Guy Gadboit]

>> I can add another disadvantage of that position to the one he
>> mentioned (aerodynamics) - it reduces how hard you can brake. Because
>> of weight distribution?

> How DID you guess? :-) That position can move the aggregate centre of
> gravity from (say) 90 cm to 120 cm above the ground. Much better
> visibility, but much easier to go over.

Actually I guessed wrong :) I thought you mean front-to-rear
distribution meaning not enough weight on the front wheel. But this
wouldn't ultimately affect braking because you can just use the rear
brake a bit more and it should work out nearly the same.

Yes you're a bit higher up, but also further back. In practice it's
pretty hard to do an endo unintentionally though.

> And, in that position, the requirement for a very narrow saddle is
> essentially absent.

Perhaps this is also the reason for the very slack seat tube angles seen
on some Dutch bikes. Sort of semi-recumbent so you can sit back in the
seat more without it getting in the way of your legs.

>> If designing a frame around this kind of fit it might make sense to
>> have longer chainstays and a reasonably short top tube. Then you could
>> still sit on the seat but the weight distribution between the wheels
>> would be a bit more even.

> If that's what you want, yes. But more weight on the rear improves the
> grip on slippery stuff and improves the braking slightly. It's not
> great up steep slopes, though, as you can fall off backwards :-)

Riding most MTBs up hills steep enough that you can just ride up them is
usually a struggle to keep the front wheel down. You need to lean right
over the handlebar.

> I once rode a bicycle with a 60 degree frame angle - despite dogma, it
> makes essentially damn-all difference to the handling.

Do you mean 60 degree seat-tube angle?

> What DOES make a difference is the steering tube angle, offset and all
> that, but there's no reason the angles have to be the same.

Indeed and on most bikes these days they aren't. The head angle is
usually a bit slacker than the seat.

This guy says it was because it made frames easier to build:

http://davesbikeblog.squarespace.com/blog/2018/1/15/my-design-philosophy-explained.html

By the 1960s the parallel angle frame came into vogue. By making the
seat and head tube the same angle, the same size top tube could be
used over several sizes, tubes could be pre-mitered, and simple
frame assembly jigs could be used, thus speeding up production.

I think what he's referring to is that back in the day all they did to
make a larger frame size was make the head-tube and seat-tube longer.
The angles were all the same because you didn't want the hassle of
buying different lugs (or bending them as you built the frame which is
possible but takes time). The down-tubes were all the same anyway. If
you made the head-tube and seat-tube parallel you also conserved
top-tubes. So then all bikes would use exactly the same lugs and tubes
and you just had to decide where to chop off the seat-tube and
head-tube.

This is partly why bikes used to be taller and shorter in the larger
sizes. A classic "Italian" frame was supposed to be "square"-- seat-tube
and top-tube the same length perhaps for some sort of aesthetic
Vitruvian-man type reasons. Large-sized mass-produced frames however were
probably taller than square. These days most frames are long and short
and we seem to like lots more seatpost sticking out.

[Nick Maclaren]

In article <73e9b3af-5d4e-4746...@googlegroups.com>,

Guy Gadboit <benc....@googlemail.com> wrote:
>>> I can add another disadvantage of that position to the one he
>>> mentioned (aerodynamics) - it reduces how hard you can brake. Because
>>> of weight distribution?
>
>> How DID you guess? :-) That position can move the aggregate centre of
>> gravity from (say) 90 cm to 120 cm above the ground. Much better
>> visibility, but much easier to go over.
>
>Actually I guessed wrong :) I thought you mean front-to-rear
>distribution meaning not enough weight on the front wheel. But this
>wouldn't ultimately affect braking because you can just use the rear
>brake a bit more and it should work out nearly the same.

No, it doesn't, because braking on an upright bicycle is ultimately
limited by when the rear wheel lifts, and the higher CoG means that
happens sooner. On my roadster, that happens at c. 1/2g, compared
to c. 2/3g for people who ride knees bent in a crouch. My recumbent
trike has a high seat, but I can still manage c. 3/4g.

>Yes you're a bit higher up, but also further back. In practice it's
>pretty hard to do an endo unintentionally though.

You bet? Try doing an emergency stop down a steep hill on a bicycle
with a high CoG - I have pushed (well, pulled) DOWN some such hills
to avoid injuring myself.

>> I once rode a bicycle with a 60 degree frame angle - despite dogma, it
>> makes essentially damn-all difference to the handling.
>
>Do you mean 60 degree seat-tube angle?

Yes. I was using the old term.

>This guy says it was because it made frames easier to build:

That makes sense.

>Large-sized mass-produced frames however were
>probably taller than square. These days most frames are long and short
>and we seem to like lots more seatpost sticking out.

God help us, yes, to both. The former made their handling and braking
truly appalling, and the latter makes it virtually impossible to get
the handlebars high enough to avoid having to carry weight on the hands.
People used to turn drop handlebars upside down to avoid that, which
was insane.


Regards,
Nick Maclaren.

[Roger Merriman]

Nick Maclaren <n...@wheeler.UUCP> wrote:
> In article <73e9b3af-5d4e-4746...@googlegroups.com>,
> Guy Gadboit <benc....@googlemail.com> wrote:
>>>> I can add another disadvantage of that position to the one he
>>>> mentioned (aerodynamics) - it reduces how hard you can brake. Because
>>>> of weight distribution?
>>
>>> How DID you guess? :-) That position can move the aggregate centre of
>>> gravity from (say) 90 cm to 120 cm above the ground. Much better
>>> visibility, but much easier to go over.
>>
>> Actually I guessed wrong :) I thought you mean front-to-rear
>> distribution meaning not enough weight on the front wheel. But this
>> wouldn't ultimately affect braking because you can just use the rear
>> brake a bit more and it should work out nearly the same.
>
> No, it doesn't, because braking on an upright bicycle is ultimately
> limited by when the rear wheel lifts, and the higher CoG means that
> happens sooner. On my roadster, that happens at c. 1/2g, compared
> to c. 2/3g for people who ride knees bent in a crouch. My recumbent
> trike has a high seat, but I can still manage c. 3/4g.

I’ve noticed this on the commute bike, fairly relaxed geometry, with bar
bag and rear panniers, that the rear is much more useable, PeddleMe, ie big
cargo bikes that you hire to cart you or stuff across London, did a video
of a fully laiden bike doing a very impressive stop.

I’d would though that if having to do a emergency stop my commute bike has
it, simply due to where the weight is, but if I have even a bit of notice,
my MTB which has much more powerful brakes plus huge levels of grip can if
in position stop dead, really hugely impressive but you need to be
alert/experienced.

So in real word most of the time the commute bike has it!

>
>> Yes you're a bit higher up, but also further back. In practice it's
>> pretty hard to do an endo unintentionally though.
>
> You bet? Try doing an emergency stop down a steep hill on a bicycle
> with a high CoG - I have pushed (well, pulled) DOWN some such hills
> to avoid injuring myself.
>
>>> I once rode a bicycle with a 60 degree frame angle - despite dogma, it
>>> makes essentially damn-all difference to the handling.
>>
>> Do you mean 60 degree seat-tube angle?
>
> Yes. I was using the old term.
>
>> This guy says it was because it made frames easier to build:
>
> That makes sense.
>
>> Large-sized mass-produced frames however were
>> probably taller than square. These days most frames are long and short
>> and we seem to like lots more seatpost sticking out.
>
> God help us, yes, to both. The former made their handling and braking
> truly appalling, and the latter makes it virtually impossible to get
> the handlebars high enough to avoid having to carry weight on the hands.
> People used to turn drop handlebars upside down to avoid that, which
> was insane.
>

Lot of geometry changes looking at newer MTB’s and Gravel etc.

>
> Regards,
> Nick Maclaren.
>
Roger Merriman

[Guy Gadboit]

On Thursday, 4 February 2021 at 12:57:33 UTC, Nick Maclaren wrote:
> In article ,

> Guy Gadboit wrote:
> >>> I can add another disadvantage of that position to the one he
> >>> mentioned (aerodynamics) - it reduces how hard you can brake. Because
> >>> of weight distribution?
> >
> >> How DID you guess? :-) That position can move the aggregate centre of
> >> gravity from (say) 90 cm to 120 cm above the ground. Much better
> >> visibility, but much easier to go over.
> >
> >Actually I guessed wrong :) I thought you mean front-to-rear
> >distribution meaning not enough weight on the front wheel. But this
> >wouldn't ultimately affect braking because you can just use the rear
> >brake a bit more and it should work out nearly the same.

> No, it doesn't, because braking on an upright bicycle is ultimately
> limited by when the rear wheel lifts, and the higher CoG means that
> happens sooner.

I meant front-to-rear weight distribution doesn't make much difference
to braking, assuming no endos. It does a bit because equal weight on
both tyres, under full braking, should be the way to get the most out of
the tyres.

But if braking is limited by rear wheel lifting, which you're probably
right it is, at least on a dry road and if the CoG is high, then what
matters is the height of the CoG and also the distance from the front
axle to the vertical line through the CoG. It doesn't really matter how
far back the back wheel is for braking, although it does for traction
unless you want a drift bike.

https://www.youtube.com/watch?v=K3K3wK-AyF4

> On my roadster, that happens at c. 1/2g, compared to c. 2/3g for
> people who ride knees bent in a crouch. My recumbent trike has a high
> seat, but I can still manage c. 3/4g.

It seems that a very slack frame angle is therefore desirable for a lot
of reasons:

1. You can have a wider seat without it getting in the way.
2. You can have a long distance from the seat to the crank to avoid
pushing with bent knees while keeping CoG low.
3. You can have that long leg extension and also put your feet down
easily when you stop.

If you have a slack frame angle you also want a fairly slack head angle
in order to bring the handlebar far back enough to be reached from an
upright position, although swept-back bars will help too. Then you can
use a lot of fork offset to get the trail back to a reasonable value.
This also puts the front wheel nice and far out in front for even more
endo protection.

How slack can you go? You start to need very long chainstays just to fit
the back wheel in if it's too laid-back. Another option might be to use
a smaller rear wheel. It just means carrying two spare tubes around
which is a bit of nuisance.

You also might risk bashing your knees on the handlebar if you do stand
up on the pedals since the vertical position becomes so much further
forward. Perhaps 70 degrees or maybe even 65 is reasonable.

> >Yes you're a bit higher up, but also further back. In practice it's
> >pretty hard to do an endo unintentionally though.

> You bet? Try doing an emergency stop down a steep hill on a bicycle
> with a high CoG - I have pushed (well, pulled) DOWN some such hills
> to avoid injuring myself.

I guess I don't have such high CoGs on any of my bikes.

> >> I once rode a bicycle with a 60 degree frame angle - despite dogma, it
> >> makes essentially damn-all difference to the handling.

I'm starting to think slack seat-tube is very key to getting this kind
of fit right.

[...]

> >Large-sized mass-produced frames however were
> >probably taller than square. These days most frames are long and short
> >and we seem to like lots more seatpost sticking out.

> God help us, yes, to both. The former made their handling and braking
> truly appalling, and the latter makes it virtually impossible to get
> the handlebars high enough to avoid having to carry weight on the hands.

Except partly the long seatpost is due to sloping top-tubes. So we have
more seat-post sticking out for a given bar height. But head-tubes have
got rather short as well.

[Zebee Johnstone]

In uk.rec.cycling.moderated on Thu, 4 Feb 2021 09:35:53 -0800 (PST)

Guy Gadboit <benc....@googlemail.com> wrote:
> It seems that a very slack frame angle is therefore desirable for a lot
> of reasons:
>
> 1. You can have a wider seat without it getting in the way.
> 2. You can have a long distance from the seat to the crank to avoid
> pushing with bent knees while keeping CoG low.
> 3. You can have that long leg extension and also put your feet down
> easily when you stop.

http://www.ransbikes.com/bicycles/

Crank forward bikes are the ultimate expression of this I think.

Rans also sells low bottom bracket long wheelbase recumbents but I
think that's getting maybe too far into the slack frame idea...

Zebee

[Guy Gadboit]

On Thursday, 4 February 2021 at 19:52:10 UTC, Zebee Johnstone wrote:
> In uk.rec.cycling.moderated on Thu, 4 Feb 2021 09:35:53 -0800 (PST)

> Guy Gadboit wrote:
> > It seems that a very slack frame angle is therefore desirable for a lot
> > of reasons:
> >
> > 1. You can have a wider seat without it getting in the way.
> > 2. You can have a long distance from the seat to the crank to avoid
> > pushing with bent knees while keeping CoG low.
> > 3. You can have that long leg extension and also put your feet down
> > easily when you stop.
> http://www.ransbikes.com/bicycles/
>
> Crank forward bikes are the ultimate expression of this I think.

Very interesting! I also just saw this video of the Raleigh factory c.
1945:

https://youtu.be/XOE0DbfWqyo

Lots of cool stuff there including an explanation of why we call it the
bottom "bracket". But it looks like the regular bikes they were making
as you can see at the start of the film had frame angles of about 68
degrees or so, with sprung saddles and swept-back bars. The "sports"
bikes had steeper seat-tubes and lower bars.

> Rans also sells low bottom bracket long wheelbase recumbents but I
> think that's getting maybe too far into the slack frame idea...

It's really a continuum from modern bikes to those old Raleighs, then
the RANS bikes and finally full recumbents.

[Jaimie Vandenbergh]

On 3 Feb 2021 at 17:59:57 GMT, "Guy Gadboit" <benc....@googlemail.com>
wrote:

> One thing I don't understand is the trend for really short chainstays on
> "long low slack" MTBs. Often to the point where the seat-tube is bent
> backwards almost over the back wheel. Sometimes they then make the
> seat-tubes steeper to get the weight a little bit further forward. Maybe
> it's just so they still fit in the box after they made the front of the
> bike so long.

It's for a better downhill position. When you're going 45mph while going
30+ degrees downhill, it makes keeping hold of the bike with your thighs
easier, and therefore more stable as you bounce over rocks and tussocks.
Without it you have to hang off the back of the saddle.

Cheers - Jaimie
--
'I use a heap based stack storage system with a sorting
algorithm which has a major sort key being chronologically
determined, and heap hash key being a combination of
gravity influenced kinetic displacement with frictive and
annoyance dispersive elements.'
-- krin_o_o_'s book filing method

[Ace]

Nothing ever changes - frame fit/design has always been a black art,
where most people are pretty happy with the perceived wisdom, i.e. the
'trendy' view of what's 'good'. There's always been a few mavericks,
like this guy and Nick, who not only claim to have found a better way
but also, frequently, proselytize about it and seem to be insisting
that the rest of the world has got it all wrong.

The key for me is that what works for you may not work for all, so
I've never really understood why people bang on about it so much, just
as people are saying about this guy in the thread you refer to.
--
Ace
http://www.chaletbeauroc.com/

[Sam Wilson]

Guy Gadboit <benc....@googlemail.com> wrote:
>
> One thing I don't understand is the trend for really short chainstays on
> "long low slack" MTBs. Often to the point where the seat-tube is bent
> backwards almost over the back wheel. Sometimes they then make the
> seat-tubes steeper to get the weight a little bit further forward. Maybe
> it's just so they still fit in the box after they made the front of the
> bike so long.

To get better traction with more weight over the back wheel? Rear wheel
slip when climbing is a real problem for MTBs. Standing on the pedals is
often not an option because it unloads the backwheel and loses traction.

Sam

--
The entity formerly known as Sam.W...@ed.ac.uk
Spit the dummy to reply

[Kerr-Mudd,John]

On Wed, 03 Feb 2021 16:14:35 GMT, n...@wheeler.UUCP (Nick Maclaren)
wrote:

I gave up reading after 3 repeats of the same picture and not a sniff of
Marmite.

--
Bah, and indeed, Humbug.

[David Damerell]

Quoting Guy Gadboit <benc....@googlemail.com>:
>I meant front-to-rear weight distribution doesn't make much difference
>to braking, assuming no endos. It does a bit because equal weight on
>both tyres, under full braking, should be the way to get the most out of
>the tyres.

You simply can't have that, though - if you're under full braking on a
roughly bicycle-shaped machine, you can never have equal weight on the
tyres - even on a tandem where you can more easily lose front traction
before the rear wheel lifts.
--
David Damerell <dame...@chiark.greenend.org.uk> Distortion Field!
Today is Aponoia, February.
Tomorrow will be Epithumia, February - a weekend.

[Rob Morley]

On Thu, 4 Feb 2021 09:35:53 -0800 (PST)

Guy Gadboit <benc....@googlemail.com> wrote:

> But if braking is limited by rear wheel lifting, which you're probably
> right it is, at least on a dry road and if the CoG is high, then what
> matters is the height of the CoG and also the distance from the front
> axle to the vertical line through the CoG.
>

It's the angle of the centre of mass behind the tyre contact patch that
matters.
Good luck trying to hang off the back for hard downhill braking if your
saddle is high and wide.

[Guy Gadboit]

You can nearly always do that because you can stand on the pedals at 9:15 and
get more height that way.

But looking at those RANS bikes has got me thinking that it's not a binary
choice between upright and full recumbent, but a spectrum, defined by seat tube
slackosity.

Where you've crossed a line of some sort however is whether it's possible or
advisable to stand up on the pedals. If the seat angle is too slack this will
get very hard to do and/or cause your knees to bash the handlebar. At some
point the bike becomes suitable for seated riding only. One of my concerns
about full recumbents (which is a theoretical concern as I haven't tried one)
is whether you need suspension. On an upright bike it's nice to be able to
stand up a little bit if you are forced to eat a pothole or tackle a bump.

So something like a 68 or maybe 65 degree seat angle might be about right, like
the old roadsters used to have, if designing something around a more upright
riding position with less weight on the hands.

[Zebee Johnstone]

In uk.rec.cycling.moderated on Wed, 10 Feb 2021 14:24:16 -0800 (PST)

Guy Gadboit <benc....@googlemail.com> wrote:
> Where you've crossed a line of some sort however is whether it's possible or
> advisable to stand up on the pedals. If the seat angle is too slack this will
> get very hard to do and/or cause your knees to bash the handlebar. At some
> point the bike becomes suitable for seated riding only. One of my concerns
> about full recumbents (which is a theoretical concern as I haven't tried one)
> is whether you need suspension. On an upright bike it's nice to be able to
> stand up a little bit if you are forced to eat a pothole or tackle a bump.

Depends on the 'bent.

Neither the ones I have now or the previous 2 wheeler have suspension.
The previous one had a mesh seat back and a reasonably forgiving aluminium
frame and bumps weren't that bad. The current 2 wheeler is carbon fibre
and hardshell seat and you know it when you hit something.

The trike has a mesh sling seat and is the most comfortable of all 3.
YOu are suspended between the wheels and it takes a big bump to worry
you.

But no they are not as good as standing. Nor are they as easy to
manage in a tight corner as an upright.

But I won't go back to a wedgie for any long ride.

Zebee

[Kim Wall]

-- On 10/02/2021 22:24, Guy Gadboit wrote:
> One of my concerns
> about full recumbents (which is a theoretical concern as I haven't tried one)
> is whether you need suspension. On an upright bike it's nice to be able to
> stand up a little bit if you are forced to eat a pothole or tackle a bump.

'Need', no, but it's highly desirable for practical road-going machines
to have something to absorb bumps before they reach your spine (shocks
through the handlebars are less of a problem than on an upright, as you
aren't bearing weight on your hands). Small diameter wheels tend to
exacerbate the issue.

Hence most non-racing recumbents tend to have some sort of rear
suspension (often a simple elastomer), or at least wider tyres and a
reasonably compliant seat design. Where weight and cost allow, eg.
high-spec touring machines, both front and rear suspension is common,
and works well.

I'd rather hit a pothole on my suspended recumbent than my rigid
upright. Legs work well as shock-absorbers if you can anticipate the
impact, but your wrists still suffer.


Kim.
--

[Nick Maclaren]

In article <h9mffh-...@willow.ductilebiscuit.net>,

Kim Wall <k...@ductilebiscuit.net> wrote:
>
>I'd rather hit a pothole on my suspended recumbent than my rigid
>upright. Legs work well as shock-absorbers if you can anticipate the
>impact, but your wrists still suffer.

My experience is that it doesn't make much difference - IF you are
riding in a genuinely upright position (i.e. with no weight on your
hands). The jarring is from the handlebars being wrenched sideways
and/or your body being thrown forward.


Regards,
Nick Maclaren.

[Nick Maclaren]

In article <894228fe-4034-4857...@googlegroups.com>,

Guy Gadboit <benc....@googlemail.com> wrote:
>
>Where you've crossed a line of some sort however is whether it's possible or
>advisable to stand up on the pedals. If the seat angle is too slack this will
>get very hard to do and/or cause your knees to bash the handlebar. At some
>point the bike becomes suitable for seated riding only. One of my concerns
>about full recumbents (which is a theoretical concern as I haven't tried one)
>is whether you need suspension. On an upright bike it's nice to be able to
>stand up a little bit if you are forced to eat a pothole or tackle a bump.
>
>So something like a 68 or maybe 65 degree seat angle might be about right, like
>the old roadsters used to have, if designing something around a more upright
>riding position with less weight on the hands.

Roadsters have longer frames, and the handlebars are swept back, with
enough room for most people to stand between them. Even with a 60
degree seat angle, you could stand up without hitting anything - been
there, done that. What they weren't (and aren't) great for is the
acrobatic off-road, where you, the cycle and the road are competing
with which can throw the rider and cycle around the most. In that
sort of use, you DO hit your thighs on the handlebars - again, been
there, done that.


Regards,
Nick Maclaren.

[Guy Gadboit]

On Thursday, 11 February 2021 at 16:14:50 UTC, Nick Maclaren wrote:
> In article <894228fe-4034-4857...@googlegroups.com>,

That's interesting. There is a practical problem however with a 60
degree seat angle which is that to clear a 700c tyre you'd need around a
480mm chainstay length. This is measured from the centre of the BB shell
by convention but that still results in a actual chainstays of just over
430mm which is the longest available from Reynolds.

65 degrees however is easily achievable. Of course you can just buy a
tube but a pre-formed chainstay has a bit of a taper, often a bend, and
an ovalized bit where the crank goes so is easier and a bit nicer.

Another option would be to use a smaller rear wheel but this means
carrying two sizes of spare inner tube. It then occurred to me it is
actually just about possible to simulate this kind of bike by fitting a
26" rear wheel to a frame that's meant to have 700c. That would tip the
seat angle back by a few degrees but may make the head angle a bit too
slack for the standard fork. You would also lose a bit of pedal
clearance.

Do you have any thoughts about head-angle? A lot of those old roadsters
look parallel but this may have been just for ease for construction. I
came across this 1953 Claude Butler which is unusual (by today's
standards) for having a seat tube that's slacker than the head tube:

https://www.bikeforums.net/classic-vintage/1212118-1953-claud-butler-colson-2.html

It's a fillet-brazed frame without lugs so could have any angles the
designer wanted. The steeper head angle makes the whole thing a bit more
compact. Assuming control over the fork you can get the trail to
whatever you need and the steering will be mostly the same. It seems to
me it mainly affects weight distribution, the overall size and how much
you need to sweep the handlebar back.

[Nick Maclaren]

In article <9829be08-2291-4419...@googlegroups.com>,

Guy Gadboit <benc....@googlemail.com> wrote:
>
>That's interesting. There is a practical problem however with a 60
>degree seat angle which is that to clear a 700c tyre you'd need around a
>480mm chainstay length. This is measured from the centre of the BB shell
>by convention but that still results in a actual chainstays of just over
>430mm which is the longest available from Reynolds.
>
>65 degrees however is easily achievable. Of course you can just buy a
>tube but a pre-formed chainstay has a bit of a taper, often a bend, and
>an ovalized bit where the crank goes so is easier and a bit nicer.

I know of no roadsters that used either the lightweight steels or
very fancy shapes (though tubes formed into arcs were fairly common).
The point is that the claimed advantages of those were all for road
racing and similar uses, and there are serious disadvantages for the
uses roadsters were designed for.

Roadsters were designed for travelling long distances over the roads
of the 1920s, and you want a very stiff frame; weight is far less
important than durability and the reduction of strain on the rider.
That's why I used to ride fairly comfortably over roads that caused
modern road-racers major difficulties, and for times that most MTB
riders baulked at.

If you want maximum speed or 'sportiness', they aren't good.


Regards,
Nick Maclaren.

[Nick Maclaren]

In article <9829be08-2291-4419...@googlegroups.com>,

Guy Gadboit <benc....@googlemail.com> wrote:
>
>Do you have any thoughts about head-angle? A lot of those old roadsters
>look parallel but this may have been just for ease for construction. I
>came across this 1953 Claude Butler which is unusual (by today's
>standards) for having a seat tube that's slacker than the head tube:
>
>https://www.bikeforums.net/classic-vintage/1212118-1953-claud-butler-colson-2.html
>
>It's a fillet-brazed frame without lugs so could have any angles the
>designer wanted. The steeper head angle makes the whole thing a bit more
>compact. Assuming control over the fork you can get the trail to
>whatever you need and the steering will be mostly the same. It seems to
>me it mainly affects weight distribution, the overall size and how much
>you need to sweep the handlebar back.

Sorry - I forgot to reply to this. Claude Butler was solidly in the
road-racer camp, and that head-tube angle is far steeper than on any
roadster I have ever seen. Also, it has caliper brakes (i.e. Endrick
rims), the handlebars are offset forward by several inches, and the
tubing (especially the rear stays) is very thin. All of which show
its road-racer heritage. For a typical roadster of that era, look
at:

http://raleighbikedealer.com/1950-raleigh-bikes/


Regards,
Nick Maclaren.

[Roger Merriman]

Even with quite gentle off road such as the old track bed of a railway in
my experience a roadster my folks have a old BSA, unless you keep the speed
down can feel it wandering, as you roll over the track bed, fine for on
tarmac but even quite tame dirt roads it doesn’t feel as planted or as
comfortable to be honest, vs stuff like my Gravel bike with similar sized
tires.

It’s still a nice bike though would love to find use for it at some point.

Roger Merriman

[Nick Maclaren]

In article <s0692n$dfn$1...@dont-email.me>,

Roger Merriman <ro...@sarlet.com> wrote:
>
>Even with quite gentle off road such as the old track bed of a railway in
>my experience a roadster my folks have a old BSA, unless you keep the speed
>down can feel it wandering, as you roll over the track bed, fine for on
>tarmac but even quite tame dirt roads it doesn't feel as planted or as
>comfortable to be honest, vs stuff like my Gravel bike with similar sized
>tires.

What era BSA? After the Raleigh take-over (1957), the BSA brand was
used for a variety of bicycles, and I don't remember any being true
roadsters. Remember that utility bicycles were not quite the same,
even in the 1950s, and (for example) usually had 26x1.375" tyres
rather than 28x1.5" ones and shorter wheelbases. See GarethPJ in:

https://forum.bikeradar.com/discussion/12597925/raleigh-made-bsa-bicycle-bsc-iso-standards-or-raleigh

I have never ridden a gravel bike, so I can believe that it wanders
less. The real problem, however, was not the wandering, but the
front fork or frame oscillating, which happened badly on most of the
'lightweight tourers'. Roadsters were effectively immune, as they had
to be, if you were going to spend many hours a day riding over lumpy
going. Gravel doesn't cause that much, though it's very bad for
wandering.


Regards,
Nick Maclaren.

[Guy Gadboit]

On Friday, 12 February 2021 at 13:19:36 UTC, Nick Maclaren wrote:
> In article <9829be08-2291-4419...@googlegroups.com>,

> Guy Gadboit wrote:
> >
> >That's interesting. There is a practical problem however with a 60
> >degree seat angle which is that to clear a 700c tyre you'd need around a
> >480mm chainstay length. This is measured from the centre of the BB shell
> >by convention but that still results in a actual chainstays of just over
> >430mm which is the longest available from Reynolds.
> >
> >65 degrees however is easily achievable. Of course you can just buy a
> >tube but a pre-formed chainstay has a bit of a taper, often a bend, and
> >an ovalized bit where the crank goes so is easier and a bit nicer.

> I know of no roadsters that used either the lightweight steels or
> very fancy shapes (though tubes formed into arcs were fairly common).
> The point is that the claimed advantages of those were all for road
> racing and similar uses, and there are serious disadvantages for the
> uses roadsters were designed for.

What are the disadvantages? I'm thinking of making a slack seat-tube
frame and was thinking of Reynolds 525 or 631 as it's now 2021 and these
tubes are not overly expensive. It's easy to get a lot of stiffness by
using oversize diameter tubes but for comfort I was thinking the thinner
ones would be better.

My 631 road bike with traditional tube sizes (1" top-tube, 1 1/8"
down-tube, wall thicknesses .8/.5/.8 and very spindly 14mm 0.6mm wall
seat stays) is very comfortable to ride even on narrow tyres. The
frame-size is about 55cm. Oversize tubing might be advisable in a larger
frame but the recipient of the slack-ST bike is smaller than I am.

> Roadsters were designed for travelling long distances over the roads
> of the 1920s, and you want a very stiff frame; weight is far less
> important than durability and the reduction of strain on the rider.

They also wanted to keep costs down.

I found these old catalogues:

https://www.sheldonbrown.com/retroraleighs/index.html#catalogues

£18 for the euphemistically named "Popular Tourist" in 1951, but about
£30 for the very sporty Reynolds 531 "Clubman".

> That's why I used to ride fairly comfortably over roads that caused
> modern road-racers major difficulties, and for times that most MTB
> riders baulked at.
>
> If you want maximum speed or 'sportiness', they aren't good.

What I'm looking for is maximum comfort over long distances tackled
slowly on roads such as they are in the UK in 2021, which is mostly not
too bad.

[Guy Gadboit]

On Friday, 12 February 2021 at 13:44:21 UTC, Nick Maclaren wrote:
> In article <9829be08-2291-4419...@googlegroups.com>,

> Guy Gadboit <> wrote:
> >
> >Do you have any thoughts about head-angle? A lot of those old roadsters
> >look parallel but this may have been just for ease for construction. I
> >came across this 1953 Claude Butler which is unusual (by today's
> >standards) for having a seat tube that's slacker than the head tube:
> >
> >https://www.bikeforums.net/classic-vintage/1212118-1953-claud-butler-colson-2.html
> >
> >It's a fillet-brazed frame without lugs so could have any angles the
> >designer wanted. The steeper head angle makes the whole thing a bit more
> >compact. Assuming control over the fork you can get the trail to
> >whatever you need and the steering will be mostly the same. It seems to
> >me it mainly affects weight distribution, the overall size and how much
> >you need to sweep the handlebar back.

> Sorry - I forgot to reply to this. Claude Butler was solidly in the
> road-racer camp, and that head-tube angle is far steeper than on any
> roadster I have ever seen. Also, it has caliper brakes (i.e. Endrick
> rims), the handlebars are offset forward by several inches, and the
> tubing (especially the rear stays) is very thin. All of which show
> its road-racer heritage.

Yes well spotted. That is definitely a very sporty bike! I just saw an
old-looking bike with a slack ST (although it does look well made and
much lower volume than a Raleigh).

[Nick Maclaren]

In article <a7b4e2df-d8ae-4dcf...@googlegroups.com>,

Guy Gadboit <benc....@googlemail.com> wrote:
>
>> I know of no roadsters that used either the lightweight steels or
>> very fancy shapes (though tubes formed into arcs were fairly common).
>> The point is that the claimed advantages of those were all for road
>> racing and similar uses, and there are serious disadvantages for the
>> uses roadsters were designed for.
>
>What are the disadvantages? I'm thinking of making a slack seat-tube
>frame and was thinking of Reynolds 525 or 631 as it's now 2021 and these
>tubes are not overly expensive. It's easy to get a lot of stiffness by
>using oversize diameter tubes but for comfort I was thinking the thinner
>ones would be better.

The frame flex problem I mentioned in a previous post. Every time
you hit the front wheel aslant on a lump, it will turn the wheel.
If that starts the fork or frame oscillating, you have to bring it
back under control fast; even for people with good reactions and
adequate balance, that's incredibly tiring if it happens every few
seconds for many hours. If it's a shallow rut and the steering has
spring, you have to over-compensate to get it straight, and then do
the converse to correct for the over-compensation. For every form
of steered vehicle except bicycles, spring in the steering linkage
is a serious no-no, but the dogma was that it is good for bicycles!

As you say, that's not the problem it was on most UK roads, and (for
some reason, possibly the unsuitability of most modern bicycles),
there are few cyclists who do extended touring over bridleways.
I can remember when that was more common, and I am not THAT old!

Also, durability and fixability. Those fancy steels needed brazing
(and still do?), but ordinary ones can be welded. Not merely is that
less prone to failure, it could be fixed by any good blacksmith. The
same was true for actual tube damage, whether being bent out of shape
or in some other ways. 'Mild' steels are incredibly forgiving. Yes,
this mattered mainly for people who toured in remote or backward places.


Regards,
Nick Maclaren.

[Guy Gadboit]

On Friday, 12 February 2021 at 18:08:06 UTC, Nick Maclaren wrote:
> In article <a7b4e2df-d8ae-4dcf...@googlegroups.com>,

> Guy Gadboit wrote:
> >
> >> I know of no roadsters that used either the lightweight steels or
> >> very fancy shapes (though tubes formed into arcs were fairly common).
> >> The point is that the claimed advantages of those were all for road
> >> racing and similar uses, and there are serious disadvantages for the
> >> uses roadsters were designed for.
> >
> >What are the disadvantages? I'm thinking of making a slack seat-tube
> >frame and was thinking of Reynolds 525 or 631 as it's now 2021 and these
> >tubes are not overly expensive. It's easy to get a lot of stiffness by
> >using oversize diameter tubes but for comfort I was thinking the thinner
> >ones would be better.

> The frame flex problem I mentioned in a previous post. Every time
> you hit the front wheel aslant on a lump, it will turn the wheel.

Yes, I should have read that post before replying to the first one :)
But very oversize tubes are available now and these are often used in
full off-road MTBs. These are extremely stiff in spite of having thin walls
because of course the diameter is much more important.

Most road-bikes now have also moved away from traditional 1" top tube
sizing but I think that feels really nice to ride on the road. You're
right it would probably be pretty squirrelly and horrible on gravel.

> If that starts the fork or frame oscillating, you have to bring it
> back under control fast; even for people with good reactions and
> adequate balance, that's incredibly tiring if it happens every few
> seconds for many hours. If it's a shallow rut and the steering has
> spring, you have to over-compensate to get it straight, and then do
> the converse to correct for the over-compensation. For every form
> of steered vehicle except bicycles, spring in the steering linkage
> is a serious no-no, but the dogma was that it is good for bicycles!
>
> As you say, that's not the problem it was on most UK roads, and (for
> some reason, possibly the unsuitability of most modern bicycles),
> there are few cyclists who do extended touring over bridleways.
> I can remember when that was more common, and I am not THAT old!
>
>
> Also, durability and fixability. Those fancy steels needed brazing
> (and still do?)

They're all weldable now. And 631/853 especially is designed for
welding. The claim is that it it's "air-hardening" and the heat cycle
from welding actually makes it stronger.

Many people do still braze frames because it's kind of an art but all
the frames I've made were TIG welded.

Those old Raleighs were typically brazed in a hearth using lugs, using a
gas flame (perhaps "town gas"?) with no added oxygen. Not because the
material couldn't withstand welding but just because this was easier and
cheaper at the time.

> but ordinary ones can be welded. Not merely is that less prone to
> failure, it could be fixed by any good blacksmith.

I don't know that you get too many blacksmiths around these days :) But
a frame made of mild steel will be thicker wall (over 1mm) and in the
range where it can therefore be buzzed together with a MIG welder. In
fact most mass-produced low-cost bikes are robot MIG welded mild steel.

A thinner-walled frame made of HSLA steel is still very repairable but
requires TIG and someone who's had a bit of practice on thin stuff.

> The same was true for actual tube damage, whether being bent out of
> shape or in some other ways. 'Mild' steels are incredibly forgiving.
> Yes, this mattered mainly for people who toured in remote or backward
> places.

Yes mild steel is incredibly forgiving, but so is cromoly/similar HSLA steels
provided it's not heat-treated (which the higher end ones are).
It's very similar to work with, just thinner and stronger.

[Danny Colyer]

On 11/02/2021 09:18, Zebee Johnstone wrote:
> In uk.rec.cycling.moderated on Wed, 10 Feb 2021 14:24:16 -0800 (PST)
> Guy Gadboit <benc....@googlemail.com> wrote:
>> One of my concerns
>> about full recumbents (which is a theoretical concern as I haven't tried one)
>> is whether you need suspension. On an upright bike it's nice to be able to
>> stand up a little bit if you are forced to eat a pothole or tackle a bump.
>
> Depends on the 'bent.
>
> Neither the ones I have now or the previous 2 wheeler have suspension.
> The previous one had a mesh seat back and a reasonably forgiving aluminium
> frame and bumps weren't that bad. The current 2 wheeler is carbon fibre
> and hardshell seat and you know it when you hit something.

Didn't you have a Bacchetta?

There may be roads somewhere in the UK that would be OK on my Bacchetta
but, if so, they're not in South Gloucestershire. Mine doesn't have a
mesh seat, though.

I intend to replace my 700c wheels with 559s, to give me clearance for
fatter tyres, which I hope will improve the ride.

When I had the same seat and wheels on the MetaBikes frame, though the
ride was fine without suspension.

--
Danny Colyer
"I'm riding a unicycle with my pants down. This should be every boy's
dream." - Bartholomew J Simpson

[Roger Merriman]

Nick Maclaren <n...@wheeler.UUCP> wrote:
> In article <s0692n$dfn$1...@dont-email.me>,
> Roger Merriman <ro...@sarlet.com> wrote:
>>
>> Even with quite gentle off road such as the old track bed of a railway in
>> my experience a roadster my folks have a old BSA, unless you keep the speed
>> down can feel it wandering, as you roll over the track bed, fine for on
>> tarmac but even quite tame dirt roads it doesn't feel as planted or as
>> comfortable to be honest, vs stuff like my Gravel bike with similar sized
>> tires.
>
> What era BSA? After the Raleigh take-over (1957), the BSA brand was
> used for a variety of bicycles, and I don't remember any being true
> roadsters. Remember that utility bicycles were not quite the same,
> even in the 1950s, and (for example) usually had 26x1.375" tyres
> rather than 28x1.5" ones and shorter wheelbases. See GarethPJ in:
>
> https://forum.bikeradar.com/discussion/12597925/raleigh-made-bsa-bicycle-bsc-iso-standards-or-raleigh
>

Can’t remember to be honest. And be a long time I suspect yet before I can
visit!

> I have never ridden a gravel bike, so I can believe that it wanders
> less. The real problem, however, was not the wandering, but the
> front fork or frame oscillating, which happened badly on most of the
> 'lightweight tourers'. Roadsters were effectively immune, as they had
> to be, if you were going to spend many hours a day riding over lumpy
> going. Gravel doesn't cause that much, though it's very bad for
> wandering.
>

The track bed has the indents left from sleepers still in some sections
which is what the stuff like that old BSA really don’t like, where the
gravel even with broadly similar sized tires doesn’t jar or thud, across
the washboard.

Deep gravel would pushing ones luck with that bike I as the tires where
lightly treaded, and the frame isn’t intended for such.

Though could do it, just required some mechanical kindness and technical
skill. I spent a lot of my youth doing so on that and similar bikes.

It’s in fairness the sort of thing that looks quite tame but does test
bikes, unless it’s a full suspension MTB which just floats across but most
bikes have to work to cross at even moderate speed.

[Nick Maclaren]

In article <s06t80$6ej$1...@dont-email.me>,

Roger Merriman <ro...@sarlet.com> wrote:
>>
>The track bed has the indents left from sleepers still in some sections
>which is what the stuff like that old BSA really don't like, where the
>gravel even with broadly similar sized tires doesn't jar or thud, across
>the washboard.

That's definitely not something any roadster I have ridden would handle
well! Their great advantage for my sort of riding is that they are
adequately fast and comfortable on anything from smooth tarmac down to
the better farm tracks and firm, short grass. But there comes a point
where things are just too much. Surprise, surprise.

The thing that I regret on my trike is that point occurs a lot earlier
than on my roadster, but I am really not up to riding the latter over
that sort of thing any more. And there's no point in even trying any
other kind of bicycle :-(

Currently, I am hoping to go to Dumfries and Galloway when lockdown
ends, and see what the forestry tracks there are like. With luck,
enough of them will be ridable on the trike - and, if not, there are
some extremely minor roads.


Regards,
Nick Maclaren.

[Zebee Johnstone]

In uk.rec.cycling.moderated on Fri, 12 Feb 2021 20:53:52 +0000

Danny Colyer <news...@colyer.plus.com> wrote:
> On 11/02/2021 09:18, Zebee Johnstone wrote:
>> In uk.rec.cycling.moderated on Wed, 10 Feb 2021 14:24:16 -0800 (PST)
>> Guy Gadboit <benc....@googlemail.com> wrote:
>>> One of my concerns
>>> about full recumbents (which is a theoretical concern as I haven't tried one)
>>> is whether you need suspension. On an upright bike it's nice to be able to
>>> stand up a little bit if you are forced to eat a pothole or tackle a bump.
>>
>> Depends on the 'bent.
>>
>> Neither the ones I have now or the previous 2 wheeler have suspension.
>> The previous one had a mesh seat back and a reasonably forgiving aluminium
>> frame and bumps weren't that bad. The current 2 wheeler is carbon fibre
>> and hardshell seat and you know it when you hit something.
>
> Didn't you have a Bacchetta?

Yeah I had a Giro. Mesh back, padded seat.

>
> There may be roads somewhere in the UK that would be OK on my Bacchetta
> but, if so, they're not in South Gloucestershire. Mine doesn't have a
> mesh seat, though.

biiig difference between mesh and hardshell. Also between the 2" of
padding on the Giro arseperch and even a thick ventsit pad.

The carbon fibre Encore is definitely not "plush".

MInd you I have a wider rear tyre on it now and that has made a bit of
difference. Doesn't bother me enough to go to something like a Big
Apple though.

Zebee

[Roger Merriman]

Nick Maclaren <n...@wheeler.UUCP> wrote:
> In article <s06t80$6ej$1...@dont-email.me>,
> Roger Merriman <ro...@sarlet.com> wrote:
>>>
>> The track bed has the indents left from sleepers still in some sections
>> which is what the stuff like that old BSA really don't like, where the
>> gravel even with broadly similar sized tires doesn't jar or thud, across
>> the washboard.
>
> That's definitely not something any roadster I have ridden would handle
> well! Their great advantage for my sort of riding is that they are
> adequately fast and comfortable on anything from smooth tarmac down to
> the better farm tracks and firm, short grass. But there comes a point
> where things are just too much. Surprise, surprise.

Yup with the Gravel it can cope with MTB trails but hits a point that it’s
doable but actually not fun.

>
> The thing that I regret on my trike is that point occurs a lot earlier
> than on my roadster, but I am really not up to riding the latter over
> that sort of thing any more. And there's no point in even trying any
> other kind of bicycle :-(
>
> Currently, I am hoping to go to Dumfries and Galloway when lockdown
> ends, and see what the forestry tracks there are like. With luck,
> enough of them will be ridable on the trike - and, if not, there are
> some extremely minor roads.
>

Not unsurprisingly wetter it is more technical it becomes, I have stuff
locally to me that in summer is fine on the Gravel, but at the moment it’s
really MTB only or at least comfortably.

[Rob Morley]

On Thu, 11 Feb 2021 11:45:00 -0800 (PST)
Guy Gadboit <benc....@googlemail.com> wrote:

> That's interesting. There is a practical problem however with a 60
> degree seat angle which is that to clear a 700c tyre you'd need
> around a 480mm chainstay length. This is measured from the centre of
> the BB shell by convention but that still results in a actual
> chainstays of just over 430mm which is the longest available from
> Reynolds.

Wishbone chainstays. Sorted.

[Guy Gadboit]

Yes that's a good suggestion. Possibly with a sort of dummy second BB shell at the end of the wishbone to attach the chainstays to which also might be a good place for a rear suspension pivot if you had rear suspension.

[Nick Maclaren]

In article <s070as$tti$1...@dont-email.me>,

As you say. There are farm track / bridleways near me that I use which
are easy on the trike in dry weather (if slow), but I often have to get
off and push (getting my feet muddy) in wet weather. People from dry
places and those who ride entirely on groomed roads don't understand why
I favour tyres like the Marathon Plus Tour and Marathon Mondial. I tried
the Marathon Supreme and, as soon as it encounters any mud, it gives up
even trying to grip.

Do you know the Dumfries and Galloway area? If so, I should like to
pick your brains. I have walked there once, long ago, but don't know
how trikable the tracks are.


Regards,
Nick Maclaren.

[Danny Colyer]

On 12/02/2021 22:21, Zebee Johnstone wrote:
> biiig difference between mesh and hardshell. Also between the 2" of
> padding on the Giro arseperch and even a thick ventsit pad.

No doubt. I've never been keen on mesh seats, though. The current seat
was really comfy on the Meta, not so much on the Giro :-(

> MInd you I have a wider rear tyre on it now and that has made a bit of
> difference. Doesn't bother me enough to go to something like a Big
> Apple though.

I started with 28-622 Durano Plus, which were absolutely fine on the
Meta. But then the Meta frame broke and I ended up having the parts
transferred to the Bacchetta frame.

After a year I switched to 37-622 tyres, because that was the widest I
had clearance for.

I now have the parts to build a couple of 26" wheels, and 60-559 Big
Apples ready to fit to them. Should make a difference.

[Nick Maclaren]

In article <VZGdndVjo4ecTLr9...@brightview.co.uk>,

Danny Colyer <news...@colyer.plus.com> wrote:
>
>After a year I switched to 37-622 tyres, because that was the widest I
>had clearance for.
>
>I now have the parts to build a couple of 26" wheels, and 60-559 Big
>Apples ready to fit to them. Should make a difference.

It certainly should! Please keep us informed. I should also be
interested to know whether it is a real 60mm - the nominally 50mm
Big Apple is only about 44mm.


Regards,
Nick Maclaren.

[Roger Merriman]

Nick Maclaren <n...@wheeler.UUCP> wrote:
> In article <s070as$tti$1...@dont-email.me>,
> Roger Merriman <ro...@sarlet.com> wrote:
>>>
>>> Currently, I am hoping to go to Dumfries and Galloway when lockdown
>>> ends, and see what the forestry tracks there are like. With luck,
>>> enough of them will be ridable on the trike - and, if not, there are
>>> some extremely minor roads.
>>>
>> Not unsurprisingly wetter it is more technical it becomes, I have stuff
>> locally to me that in summer is fine on the Gravel, but at the moment it's
>> really MTB only or at least comfortably.
>
> As you say. There are farm track / bridleways near me that I use which
> are easy on the trike in dry weather (if slow), but I often have to get
> off and push (getting my feet muddy) in wet weather. People from dry
> places and those who ride entirely on groomed roads don't understand why
> I favour tyres like the Marathon Plus Tour and Marathon Mondial. I tried
> the Marathon Supreme and, as soon as it encounters any mud, it gives up
> even trying to grip.

I haven’t noticed much between the BigApples and the Marathon Plus Touring
at least on the commute, one of my routes gets flooded boggy in winter, and
both in 26/2inch form clog up and squirm, it’s a old MTB so still fine more
bothered by the water and debris getting into the gear cable and drive
chain though that is much easier to just was off.

>
> Do you know the Dumfries and Galloway area? If so, I should like to
> pick your brains. I have walked there once, long ago, but don't know
> how trikable the tracks are.
>

Don’t think I have to be honest, I don’t remember but such is life.

[Roger Merriman]

Probably depends on rims, well it most certainly will!

I will see if I have anything I can measure tomorrow maybe!

Roger Merriman

[Rob Morley]

On Sat, 13 Feb 2021 01:50:46 -0800 (PST)
Guy Gadboit <benc....@googlemail.com> wrote:

> On Saturday, 13 February 2021 at 03:36:32 UTC, Rob Morley wrote:

> > Wishbone chainstays. Sorted.
>
> Yes that's a good suggestion. Possibly with a sort of dummy second BB
> shell at the end of the wishbone to attach the chainstays to which

Perhaps a round tube slightly larger diameter than the chainstays, to
make a neat junction between the stays and the bottom bracket
extension. You could put fancy engraved caps on the tube ends for extra
added boutique effect.

> also might be a good place for a rear suspension pivot if you had
> rear suspension.

Depending on the linkage arrangement ... you often want the main pivot
at the same height as the chainring(s) to reduce suspension movement
effect on chain tension (and chain tension effect on suspension
movement).

[Danny Colyer]

On 13/02/2021 14:30, Nick Maclaren wrote:
>> I now have the parts to build a couple of 26" wheels, and 60-559 Big
>> Apples ready to fit to them. Should make a difference.
>
> It certainly should! Please keep us informed. I should also be
> interested to know whether it is a real 60mm - the nominally 50mm
> Big Apple is only about 44mm.

I will. I doubt that I'll get to it before the summer.

FWIW I already have two Big Apples on unicycles. I've just measured the
60-559 at 59mm. The 60-622 is currently deflated and I can't easily get
to it to pump it up.

[Guy Gadboit]

On Sunday, 14 February 2021 at 11:00:16 UTC, Rob Morley wrote:
> On Sat, 13 Feb 2021 01:50:46 -0800 (PST)
> Guy Gadboit <> wrote:
>
> > On Saturday, 13 February 2021 at 03:36:32 UTC, Rob Morley wrote:
>
> > > Wishbone chainstays. Sorted.
> >
> > Yes that's a good suggestion. Possibly with a sort of dummy second BB
> > shell at the end of the wishbone to attach the chainstays to which

> Perhaps a round tube slightly larger diameter than the chainstays, to
> make a neat junction between the stays and the bottom bracket
> extension. You could put fancy engraved caps on the tube ends for extra
> added boutique effect.

I like it :)

The tube going back from the BB shell would want to be nice and stiff
since there's only one of it. So large diameter. Then the dummy BB would
want to be about the same diameter since mitring a fat tube onto a
thinner one is never ideal. So they'd probably both be about 35mm or so.

The second "BB shell" could also be a bit wider for oodles of tyre
clearance.

> > also might be a good place for a rear suspension pivot if you had
> > rear suspension.

> Depending on the linkage arrangement ... you often want the main pivot
> at the same height as the chainring(s) to reduce suspension movement
> effect on chain tension (and chain tension effect on suspension
> movement).

Yes good point.

It could be at the same height-- you could go straight back from the BB
shell to the extension, and the chainstays could go up a bit from there
(they usually go up a bit because most bikes have a positive BB drop.

But it would still affect the length of the chain. The ideal place for
the pivot would be concentric with the actual BB shell. I wonder if
anyone does put it there.

Also I say that's ideal but there are other considerations which I don't
really understand... but would be fun to make a full-suss one day.

[Nick Maclaren]

In article <f011373a-d2d1-406c...@googlegroups.com>,

Guy Gadboit <benc....@googlemail.com> wrote:
>
>> > also might be a good place for a rear suspension pivot if you had
>> > rear suspension.
>
>> Depending on the linkage arrangement ... you often want the main pivot
>> at the same height as the chainring(s) to reduce suspension movement
>> effect on chain tension (and chain tension effect on suspension
>> movement).
>
>Yes good point.
>
>It could be at the same height-- you could go straight back from the BB
>shell to the extension, and the chainstays could go up a bit from there
>(they usually go up a bit because most bikes have a positive BB drop.
>
>But it would still affect the length of the chain. The ideal place for
>the pivot would be concentric with the actual BB shell. I wonder if
>anyone does put it there.
>
>Also I say that's ideal but there are other considerations which I don't
>really understand... but would be fun to make a full-suss one day.

It would have MASSIVE advantages, but mostly for reasons that are
generally ignored. You could put a hub gear there, and not suffer
the torque limitations as much, with either very low gears or electric
assist. And you could put a full chaincase on, thus making the cycle
clean to ride, removing the need for regular cleaning/oiling/waxing,
AND making the cycle suitable for off-roading through overgrown paths.
All you need for the latter is two concentric sockets.

And you could combine that with a really simple two-gear rear hub,
giving a step-down of up to 4:1, delivering a gear range of (say)
5"-100". For dead spot reasons, gears of lower than 5" are almost
useless, so that is all anyone would be able to use.


Regards,
Nick Maclaren.

[Guy Gadboit]

On Sunday, 14 February 2021 at 18:07:53 UTC, Nick Maclaren wrote:
> In article <f011373a-d2d1-406c...@googlegroups.com>,

> Guy Gadboit <> wrote:
> >
[...]

> >But it would still affect the length of the chain. The ideal place for
> >the pivot would be concentric with the actual BB shell. I wonder if
> >anyone does put it there.
> >
> >Also I say that's ideal but there are other considerations which I don't
> >really understand... but would be fun to make a full-suss one day.

> It would have MASSIVE advantages, but mostly for reasons that are
> generally ignored. You could put a hub gear there, and not suffer
> the torque limitations as much, with either very low gears or electric
> assist.

What are the torque limitations? Are you saying it's better to have the
gears at the crank than at the hub?

> And you could put a full chaincase on, thus making the cycle
> clean to ride, removing the need for regular cleaning/oiling/waxing,
> AND making the cycle suitable for off-roading through overgrown paths.
> All you need for the latter is two concentric sockets.
>
> And you could combine that with a really simple two-gear rear hub,
> giving a step-down of up to 4:1, delivering a gear range of (say)
> 5"-100". For dead spot reasons, gears of lower than 5" are almost
> useless, so that is all anyone would be able to use.

Full chaincases are definitely a plus. Another way you could do it is
with two chains, one from the real BB to the second BB, fully enclosed,
and another from the second BB to the rear wheel, also fully enclosed,
on the other side.

The second BB would be enlarged a bit and effectively contain the motor
as well as the rear suspension pivot concentric with the drive shaft.
The gears would probably be in the front BB I guess since I think you're
saying that's better. The chain from the motor to the rear wheel would
probably be a gear reduction since that's normally what motors like.

[Guy Gadboit]

On Sunday, 14 February 2021 at 22:37:48 UTC, Guy Gadboit wrote:
> On Sunday, 14 February 2021 at 18:07:53 UTC, Nick Maclaren wrote:
> > In article <f011373a-d2d1-406c...@googlegroups.com>,
> > Guy Gadboit <> wrote:
> > >
> [...]
> > >But it would still affect the length of the chain. The ideal place for
> > >the pivot would be concentric with the actual BB shell. I wonder if
> > >anyone does put it there.

I just remembered where I have seen a full-suspension that pivoted around the crank and had an enclosed chain. Allen Millyard's downhill bike:

https://dirtmountainbike.com/features/railroad-millyard-invention.html

It also has the gears up by the crank. Very good design.

[Sam Wilson]

Rob Morley <nos...@ntlworld.com> wrote:
> On Sat, 13 Feb 2021 01:50:46 -0800 (PST)
> Guy Gadboit <benc....@googlemail.com> wrote:
>
>> On Saturday, 13 February 2021 at 03:36:32 UTC, Rob Morley wrote:
>
>>> Wishbone chainstays. Sorted.
>>
>> Yes that's a good suggestion. Possibly with a sort of dummy second BB
>> shell at the end of the wishbone to attach the chainstays to which
>
> Perhaps a round tube slightly larger diameter than the chainstays, to
> make a neat junction between the stays and the bottom bracket
> extension. You could put fancy engraved caps on the tube ends for extra
> added boutique effect.

How do chainstay cross sections compare to fork blades? I ask because I
once helped build a couple of frames. One was lugged but the other was
lugless. Both brazed 531. The lugless one was particularly tall and for
reasons I can’t remember there was a problem with the seat stays being too
short so a wishbone-type construction was built with a short length of some
other tube (can’t remember where it came from) and a cut down fork crown,
shaved to make the stubs fit the chainstays. If forks and chainstays are
similar sizes then using a fork crown might work.

Sam

--
The entity formerly known as Sam.W...@ed.ac.uk
Spit the dummy to reply

[Guy Gadboit]

On Monday, 15 February 2021 at 13:34:03 UTC, Sam Wilson wrote:
> Rob Morley <nos...@ntlworld.com> wrote:
> > On Sat, 13 Feb 2021 01:50:46 -0800 (PST)
> > Guy Gadboit <> wrote:
> >
> >> On Saturday, 13 February 2021 at 03:36:32 UTC, Rob Morley wrote:
> >
> >>> Wishbone chainstays. Sorted.
> >>
> >> Yes that's a good suggestion. Possibly with a sort of dummy second BB
> >> shell at the end of the wishbone to attach the chainstays to which
> >
> > Perhaps a round tube slightly larger diameter than the chainstays, to
> > make a neat junction between the stays and the bottom bracket
> > extension. You could put fancy engraved caps on the tube ends for extra
> > added boutique effect.

> How do chainstay cross sections compare to fork blades?

Forks are usually a bit bigger but I think you can get chainstays that
are the same size as forks. There are all kinds of different sizes of
chainstay in the Columbus catalogue. Much less choice with Reynolds.

> I ask because I once helped build a couple of frames. One was lugged
> but the other was lugless. Both brazed 531. The lugless one was
> particularly tall and for reasons I can’t remember there was a problem
> with the seat stays being too short so a wishbone-type construction
> was built with a short length of some other tube (can’t remember where

> it came from).

Could have been an offcut from one of the main tubes on a smaller frame.

> and a cut down fork crown, shaved to make the stubs fit
> the chainstays.

ITYM seatstays?

> If forks and chainstays are similar sizes then using a fork crown
> might work.

Yes I think it easily could if you made sure to buy the right parts. But
the only reason to use a fork crown is if you need a socket to flow
braze into. With welding it's easier to just weld a bit of tube on. And
you don't usually use fork crowns at all for welded forks. You either
make a unicrown fork and just weld the curved legs directly onto the
steerer or you can make a "segmented" fork out of bits of old steerer
tube.

I think the slack ST frame I'm going to make will have 26" wheels anyway
and will probably work without a wishbone. I'm going to make an
adjustable "fitting bike" first to see what some of these more
non-standard (by today's standards) seating positions are actually like.

[Tosspot]

On 04/02/2021 17:17, Roger Merriman wrote:

<snip>

> I’ve noticed this on the commute bike, fairly relaxed geometry, with
> bar bag and rear panniers, that the rear is much more useable,
> PeddleMe, ie big cargo bikes that you hire to cart you or stuff
> across London, did a video of a fully laiden bike doing a very
> impressive stop.

So, the Harry vs Larry Bullitt is built and needs a longer run, what
better than the 5 miles to the pub, especially as it's a bit down hill
on the way back...<several hours later>. The Rohloff seems geared
correctly, and these plasticky dual pot brakes seems to work OK. Lets
get up a bit of speed and test them. Back brake first, yep, that locks
up no drama, what about the front? <girly braking> that seems to work,
what about a bit more? Front wheel locks up, again no big drama. Back
up to speed. I wonder just how quick it will stop? <handful of both
brakes>...

Well, the answer is, as you say, impressive. The bike stops, the rider,
knowing what is good for him, obeys Newton's 2nd law until his crotch
hits the handlebars, at which point his lower body stops, and upper body
continues... The whole kit and caboodle finally stops and no, you can't
put your feet on the floor while doubled over the handle bars.

I think they call it a "learning experience"...

[Sam Wilson]

Guy Gadboit <benc....@googlemail.com> wrote:
>
> On Monday, 15 February 2021 at 13:34:03 UTC, Sam Wilson wrote:
>
>> and a cut down fork crown, shaved to make the stubs fit
>> the chainstays.
>
> ITYM seatstays?

I did, thank you.

[Rob Morley]

On Sun, 14 Feb 2021 14:43:15 -0000 (UTC)
Sam Wilson <u...@dummy.wislons.fastmail.co.uk> wrote:

> How do chainstay cross sections compare to fork blades? I ask
> because I once helped build a couple of frames. One was lugged but
> the other was lugless. Both brazed 531. The lugless one was
> particularly tall and for reasons I can’t remember there was a
> problem with the seat stays being too short so a wishbone-type
> construction was built with a short length of some other tube (can’t
> remember where it came from) and a cut down fork crown, shaved to
> make the stubs fit the chainstays. If forks and chainstays are
> similar sizes then using a fork crown might work.
>

If you must have lugged construction you can fabricate lugs from mild
steel sheet or tubing and TIG them together.

[Guy Gadboit]

Yes this is quite often done these days as people can't always find the
lugs they want in the angles they want.

[Danny Colyer]

On 13/02/2021 14:30, Nick Maclaren wrote:

Exactly 60mm, by my measurement.

I replaced the rear wheel a couple of weeks ago, I haven't done the
front yet. I've just taken it for a spin around the block.

It's difficult to compare the new wheel and tyre combination with the
old, both because it's 19 months since I last rode the Giro and because
it was only a short ride, mostly to test my ability to ride the bike. I
was unable to cycle for 16 months due to injury, and since I started
again I've been sticking to the less demanding Street Machine.

Whenever I hit a bump there was a small but discernible difference
between the front wheel (still running 37-662) and the rear (60-559).
It was clear, though, that 55psi is too hard for this tyre on an
unsuspended bike (on a unicycle I'd pump it up to 60). I'll reduce it
to 40 for my next ride.

[Nick Maclaren]

In article <BaWdnUzsg_hYaVD9...@brightview.co.uk>,

Danny Colyer <news...@colyer.plus.com> wrote:
>>>
>>> After a year I switched to 37-622 tyres, because that was the widest I
>>> had clearance for.
>>>
>>> I now have the parts to build a couple of 26" wheels, and 60-559 Big
>>> Apples ready to fit to them. Should make a difference.
>>
>> It certainly should! Please keep us informed. I should also be
>> interested to know whether it is a real 60mm - the nominally 50mm
>> Big Apple is only about 44mm.
>
>Exactly 60mm, by my measurement.

Thanks.

>I replaced the rear wheel a couple of weeks ago, I haven't done the
>front yet. I've just taken it for a spin around the block.
>
>It's difficult to compare the new wheel and tyre combination with the
>old, both because it's 19 months since I last rode the Giro and because
>it was only a short ride, mostly to test my ability to ride the bike. I
>was unable to cycle for 16 months due to injury, and since I started
>again I've been sticking to the less demanding Street Machine.
>
>Whenever I hit a bump there was a small but discernible difference
>between the front wheel (still running 37-662) and the rear (60-559).
>It was clear, though, that 55psi is too hard for this tyre on an
>unsuspended bike (on a unicycle I'd pump it up to 60). I'll reduce it
>to 40 for my next ride.

I would expect that. My experience with similar tyres is that they
roll well over roughish going (poor tarmac etc.) even below that.
But 40 psi sounds a good all-round pressure.


Regards,
Nick Maclaren.

[Roger Merriman]

I run 40psi on the commute bike old MTB, with 2inch so 50mm or thereabouts,
Big Apples, can feel the sidewall flex as the bike and kit is heavy, has
enough I call rattle along decking and gravel stuff with out issue.

And seems to last as long as the Marathon plus Touring in that both die
from being cut up than wear out but takes a good 8k for that to happen. But
unlike the Touring they are far more responsive feeling and make the bike
feel lovely rather than dull.

Roger Merriman

[Guy Gadboit]

Well this bike is completed. 70 degree frame angle, 72 head, 26" wheels, could have used larger ones especially on the front! Basically road-sized tubing (1" TT, 9/8" DT, 0.8/0.6mm thick) for the front triangle and more touring-bikey at the back. The rider it's intended for doesn't run with a heavy front rack (although I am making a rando rack for it) , is light herself, and doesn't ride off-road, so I don't think excessive stiffness is desirable. The whole bike is pretty light.

As you can see the HT is very long. This style of bike traditionally used rather long quill stems to achieve the required high stack. But I prefer the threadless system. The only drawback is that the standover is a bit limited. It might have been better to keep the HT that long but just join the TT a bit lower down. But I'm not a fan of the look of having an extension above the TT.

The steerer tube is the longest Reynolds supply, 420mm, and is uncut, and the fork is also pretty long (407mm axle to crown).

The chainstays are the longest I thought I could make them with the Reynolds tubes but actually the cast dropouts are so enormous I could have gone much longer. But I think this is actually a good length (450mm).

Big squishy saddle, since that's the whole point of this kind of design-- less weight on the hands more at the rear. It rides beautifully and is very comfortable, but hasn't been on any long rides yet. The tyres are a little narrower than fashion dictates these days but she wanted "shot-in" seatstays and I didn't have much luck bending them (I left enough room that I could cut them off and still use them if that failed, which it did).

https://i.imgur.com/IaQtoBj.jpg
https://i.imgur.com/IaQtoBj.jpg
https://i.imgur.com/YmH6lfk.jpg

[Danny Colyer]

On 19/06/2021 14:44, Danny Colyer wrote:
>> Danny Colyer <news...@colyer.plus.com> wrote:
>>> After a year I switched to 37-622 tyres, because that was the widest I
>>> had clearance for.
>>>
>>> I now have the parts to build a couple of 26" wheels, and 60-559 Big
>>> Apples ready to fit to them. Should make a difference.
>

> I replaced the rear wheel a couple of weeks ago, I haven't done the
> front yet. I've just taken it for a spin around the block.
>
> It's difficult to compare the new wheel and tyre combination with the
> old, both because it's 19 months since I last rode the Giro and because
> it was only a short ride, mostly to test my ability to ride the bike. I
> was unable to cycle for 16 months due to injury, and since I started
> again I've been sticking to the less demanding Street Machine.
>
> Whenever I hit a bump there was a small but discernible difference
> between the front wheel (still running 37-662) and the rear (60-559).
> It was clear, though, that 55psi is too hard for this tyre on an
> unsuspended bike (on a unicycle I'd pump it up to 60). I'll reduce it
> to 40 for my next ride.

I replaced the front wheel and tyre a couple of months ago. I've ridden
about 180 miles on them so far.

The difference was dramatic. Having a fat tyre on the front seemed to
make more difference to comfort than having one on the back. The bike
is a lot more pleasant to ride.

It's impossible to really judge the effect on speed. I'm still
recovering from injury, I've lost fitness that I'll probably never fully
recover and I'm not riding my historically usual route (WFH means I
don't have to commute, and I'm not riding into Keynsham if I don't have to).

On smooth tarmac I'm pretty sure the new wheels and tyres are slower
than the old (perhaps as much as 10% slower at speeds of around 20mph).
If I were to return to commuting on poorly-maintained roads, perhaps
that difference would be less. I won't be returning to the office this
year (I don't expect ever to return full time), so it will be a while
before I find out.

[Nick Maclaren]

In article <3e6dnSNGeaFlAND8...@brightview.co.uk>,

Danny Colyer <news...@colyer.plus.com> wrote:
>
>On smooth tarmac I'm pretty sure the new wheels and tyres are slower
>than the old (perhaps as much as 10% slower at speeds of around 20mph).

10% is implausible as that is c. 30% in power, and either or both of a
ridiculous increase in rolling resistance or a physically implausible
increase in windage. But it would probably be slower at that speed.

It might feel a LOT slower, of course, because people's perceptions of
speed are very dependent on vibration and instability. A smoother ride
often feels slower but is markedly faster - and in cars, too!

> If I were to return to commuting on poorly-maintained roads, perhaps
>that difference would be less. I won't be returning to the office this
>year (I don't expect ever to return full time), so it will be a while
>before I find out.

Or the other way round, as I find! Obviously, it depends on HOW rough,
and many other factors, including your speed.


Regards,
Nick Maclaren.

[Zebee Johnstone]

In uk.rec.cycling.moderated on Fri, 24 Sep 2021 10:44:25 +0100

Danny Colyer <news...@colyer.plus.com> wrote:
>
> The difference was dramatic. Having a fat tyre on the front seemed to
> make more difference to comfort than having one on the back. The bike
> is a lot more pleasant to ride.

THe trike is a lot more pleasant on the 42mm Conti Urbans than it was
on the 35mm Marathons and the 23mm Contis were hell.

I have not yet got up the desire to put bigger tyres on the 2 wheel
'bent but given the hardshell seat and the really noticeable
difference between it and the trike maybe I should!

Zebee