[OT kinda] Tire pressure guage
~kurt
OK, this seems weird. I just bought one of those fancy tire pressure
gauges. You know, the one with a dial, the flexible tube, etc....
I had been wanting a good quality gauge for a while, and thanks to
the RC51's larger rotors (compared to the YZF600R's) which make it
very difficult for me to get my hands anywhere near the valve stem,
I finally picked one up.
The fancy gauge (made by Draper) registers 3 psi lower than the
three cheapo pen style gauges. The 3 cheap ones all measure the
same exact pressure. Does this seem surprising? A three psi difference
seems kind of big. But I'm really wondering if the fancy gauge is off
since all three of the pen style ones agree. Anyone else with a variety
of gauges ever compare readings?
- Kurt
Larry xlax Lovisone
I had been wanting a good quality gauge for a while, and thanks to
> the RC51's larger rotors (compared to the YZF600R's) which make it
> very difficult for me to get my hands anywhere near the valve stem,
A $10.00 aluminum angle valve stem will cure your problem more than a new tire
gauge...
http://www.ferracci.com/2002ferracci/online_catalog/chassis_and_driveline/aluminumvalvestems_600.jpg
Larry L
94 RC45 #2
Have a wheelie NICE day...
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G C
A man with one watch always knows what time it is.
A man with two watches is never quite sure.
(This is why we have to calibrate our instruments regularly)
--
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'77 CB750K (Street) '78 CB750K (Cafe)
'79 FLHassle (Gone) '00 ZG1000 (Sarge)
'97 Ducati M750 (horse with no name, yet)
Pull 'mychain' to reply
krusty kritter
>OK, this seems weird. I just bought one of those fancy tire pressure gauges.
You know, the one with a dial, the flexible tube, etc....The fancy gauge (made
by Draper) registers 3 psi lower than the three cheapo pen style gauges.
The extra volume of the flexible tube and the Bourdon tube inside the gauge
might be responsible for for a pound or so of pressure difference...
And the extra volume of the tube and gauge might make setting an exact critical
pressure in a small front tire an exercise in frustration. You might have to
add air pressure to the tire when you find that checking the pressure has bled
off too much air the first time...
>A three psi difference seems kind of big.
You can accomodate for any error in the new gauge by using a little less
pressure when you inflate your tires, you'll get a feeling for what new
pressure you should use, if any changes need to be made...
>But I'm really wondering if the fancy gauge is off since all three of the pen
style ones agree.
You could buy three or four Camel tire pressure gauges from Pep Boys, check the
tire pressure on one of your car's tires, since it would have a larger volume
of air, and compare the readings of all the gauges...
Then choose one of the gauges that reads closest to the others and return the
rest of the gauges to Pep Boys. They will take them back and refund your
money...
Now, tire pressure readings aren't absolutely carved in stone, you can adjust
your tire pressures to whatever works for you, and, if somebody asks you for
tire pressure advice, you can tell him that you aren't Moses, your tire
pressure recommendations are just in a ballpark range, and tell him that you
use around XX pressure in the front and XX pressure in the rear, but that he
should experiment and always use the same gauge...
>Anyone else with a variety of gauges ever compare readings?
Yes, I got to wondering whether the tire pressure gauge I'd been using for
years was accurate. The pencil-type gauge has an air seal that can wear out and
the gauge might read higher than it should, or if the seal is really worn out,
it will leak and read low...
Also, the spring in the pencil-type gauge will get weaker over the years and
the gauge will read high...
So I went out and bought a $10 Camel digital gauge and a $3 Camel pencil-type
gauge. Both of the new Camel gauges read about 2 pounds lower than the older
penicl gauge I'd been using...
# * 0 * #
^
fl...@sportbike.com
> A man with one watch always knows what time it is.
> A man with two watches is never quite sure.
G C, Merry Christmas and you have now officially taken over the Taoist job
of Brian and PaulH.
BTW, who gives a rats ass about what the guage says? I fill my tires close
and then adjust to what the ride is telling me! I don't need hair to tell me
where lunch is!
Flash
--
Sportbike riding is not virtual reality
Andrew
You should buy a Triumph, the front wheel has a 90 degree angle stem.
--
Andrew
00 Daytona
00 Speed Triple
the fly
wrote:
I've had occasion to calibrate different types of tire gauges
more than once. Some observations from my experience:
1. Pencil-type gauges are notoriously inaccurate. All-metal
pencil-types (20 years ago and more) were generally better than the
ones with plastic stems.
2. Bourdon-tube gauges of moderately good quality are generally more
accurate than pencil-types. Repeatability is better. I'll define
"moderately good quality" here as gauges costing $15-$20 US, or more.
True, you don't always get what you pay for, but if you buy from a
reputable auto parts dealer (NOT AutoZone, Pep Boys, et al) you can
get a gauge of reasonable accuracy and quality.
3. As other posters have noted, don't depend on any gauge for
absolute accuracy. Get to know how your gauge readings correspond to
the vehicle's handling under varying conditions, and adjust your
readings accordingly. Most tire gauges are of greater value as
comparators than as laboratory-grade standards.
~kurt
>
> BTW, who gives a rats ass about what the guage says? I fill my tires close
> and then adjust to what the ride is telling me! I don't need hair to tell me
> where lunch is!
True. I am more interested in knowing what tire pressure I have been
riding at in the past so I can start with that and adjust as needed
with the new bike. I have to remember the new fancy gauge reads a few
psi lower than what I am used to.
I was also very surprised how consistent the three different pen gauges
were. They were all different brands, different ages, and didn't even
look the same. But registered the same pressure.
Having an accurate measure for pressure would be nice. Hopefully I'll
finally start having some track time this summer. I would like to start off
on the track with the recommended pressure and adjust from there.
I guess none of it matters. When I was living in Denver I would set
my tire pressure just a hair lower than I wanted because I knew the ride
in the mountains was a few thousand feet higher. Of course the temp
was lower. That meant measuring the volume of the tires, using the
gas law, etc.... (I am kidding of course - I am not that anal about
tire pressure). But damnit, a $25+ pressure gauge should be accurate to
at least 1/2 psi and should definitely not have a 3 psi bias.
- Kurt
~kurt
>
> You should buy a Triumph, the front wheel has a 90 degree angle stem.
>
I had an image of a Triumph in my head as I was squeezing my hand in there
cursing the Japanese while trying to attach the pump nozzle to the valve stem.
- Kurt
Reassembler
~kurt <actino...@netscape.net> wrote in message
news:ElsAd.6194$qf5....@newsread3.news.atl.earthlink.net...
Stick with the pen type gauges, especially when you have three that agree.
My Father worked as a tire engineer for 40 years, and he told me the dial gauges
must be calibrated regularly. A pen gauge with a 0-50 scale is as close as
you'll ever need to get. Besides, I get a three pound variation just from shade
to sun, on Maui.
Reassembler
Larry xlax Lovisone
Anyone else with a variety
> of gauges ever compare readings?
Kurt...
If you wish to know if your tire gauge is spot on... all you got to do is pack
it to a AMA race... in the pits is a tire gauge calibration station... that's
how I found out this little gem is accurate enough and small enough to carry on
Mr.RC45 where space is a premium...
http://www.autobarn.net/actirgaugkey.html
Daniel Bannon
wrote:
>The fancy gauge (made by Draper) registers 3 psi lower than the
>three cheapo pen style gauges. The 3 cheap ones all measure the
>same exact pressure. Does this seem surprising? A three psi difference
>seems kind of big. But I'm really wondering if the fancy gauge is off
>since all three of the pen style ones agree. Anyone else with a variety
>of gauges ever compare readings?
>
>- Kurt
I THINK they can be zeroed, via some sort of adjuster that should be
visible on the case.
What I'd do: go to the nearest track event (sadly, probably 3 months
away). Compare the Dunlop tire guy's reading to yours on any given
tire. Calibrate to his.
(Oh, I suppose you could use the Bridgestone guy instead!)
While not entirely scientific, that's a simple method.
Those gauges croak occasionally, for no good reason, damn the cost. I
bought a rubber cover for mine, to lessen impact trauma, but it still
gets tossed around in the kit box at track events. They don't lead an
easy life, too bad considering how big an impact they can make.
'-----------------------------------------------------
' Daniel Bannon
' NW WA State, U.S.A.
' 2003 ZX636B Hercusaki, 1999 CBR1100XX
'-----------------------------------------------------