Tire Pressure gage

(previously posted to rec.bicycles.soc by mistake)

I have a pressure gage on my tire pump but have been wondering about
whether a separate pressure gage might not be helpful. 700C 28 or 32,
presta valve, tires, at ~90 - 100 psi, and I've pumped them up
approximately every one to two weeks mainly based on the "Squeeze
Test".

I've noticed that connecting the tire pump to the tire and pumping
that the air pressure in the pump and hose rise until they overcome
the tire valve and for an instant the approximate tire pressure is
registered and sometimes if I had known the tire pressure I wouldn't
have used the pump. Thus the thought that a gage might be useful.

On the other hand, it does take a finite amount of air to operate the
gage so each time one checks the pressure it reduced the tire pressure
by some figure.
--
Cheers,

John B.

designed to minimize pressure loss. if attached with precision then the same loss each check....


http://www.universalcycles.com/shopp...?category=2119

On 4/25/2014 6:18 AM, John B. wrote:

(previously posted to rec.bicycles.soc by mistake)

I have a pressure gage on my tire pump but have been wondering about
whether a separate pressure gage might not be helpful. 700C 28 or 32,
presta valve, tires, at ~90 - 100 psi, and I've pumped them up
approximately every one to two weeks mainly based on the "Squeeze
Test".

I've noticed that connecting the tire pump to the tire and pumping
that the air pressure in the pump and hose rise until they overcome
the tire valve and for an instant the approximate tire pressure is
registered and sometimes if I had known the tire pressure I wouldn't
have used the pump. Thus the thought that a gage might be useful.

On the other hand, it does take a finite amount of air to operate the
gage so each time one checks the pressure it reduced the tire pressure
by some figure.


The better Bourdon tube style gauges bleed an absolute
minimum of air when checking:
http://www.yellowjersey.org/panag2.jpg

The British plunger type gauges were generally less well sealed:

http://s4f9b55a471ef4.img.gostorego...._1600x1067.jpg

Although much loved they are really hard to find now having
been discontinued 25 years ago.

Electronic gauges are a different topic on which I have
nothing positive to offer.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Friday, April 25, 2014 5:33:22 AM UTC-7, AMuzi wrote:
On 4/25/2014 6:18 AM, John B. wrote:



(previously posted to rec.bicycles.soc by mistake)



I have a pressure gage on my tire pump but have been wondering about

whether a separate pressure gage might not be helpful. 700C 28 or 32,

presta valve, tires, at ~90 - 100 psi, and I've pumped them up

approximately every one to two weeks mainly based on the "Squeeze

Test".



I've noticed that connecting the tire pump to the tire and pumping

that the air pressure in the pump and hose rise until they overcome

the tire valve and for an instant the approximate tire pressure is

registered and sometimes if I had known the tire pressure I wouldn't

have used the pump. Thus the thought that a gage might be useful.



On the other hand, it does take a finite amount of air to operate the

gage so each time one checks the pressure it reduced the tire pressure

by some figure.





The better Bourdon tube style gauges bleed an absolute

minimum of air when checking:

http://www.yellowjersey.org/panag2.jpg


Crap, man, that tire is running at like 400 psi! (Really, though, what is the scale used by the Japanese?)

-- Jay Beattie.

On Fri, 25 Apr 2014 07:33:22 -0500, AMuzi wrote:

On 4/25/2014 6:18 AM, John B. wrote:

(previously posted to rec.bicycles.soc by mistake)

I have a pressure gage on my tire pump but have been wondering about
whether a separate pressure gage might not be helpful. 700C 28 or 32,
presta valve, tires, at ~90 - 100 psi, and I've pumped them up
approximately every one to two weeks mainly based on the "Squeeze
Test".

I've noticed that connecting the tire pump to the tire and pumping
that the air pressure in the pump and hose rise until they overcome
the tire valve and for an instant the approximate tire pressure is
registered and sometimes if I had known the tire pressure I wouldn't
have used the pump. Thus the thought that a gage might be useful.

On the other hand, it does take a finite amount of air to operate the
gage so each time one checks the pressure it reduced the tire pressure
by some figure.


The better Bourdon tube style gauges bleed an absolute
minimum of air when checking:
http://www.yellowjersey.org/panag2.jpg

The British plunger type gauges were generally less well sealed:

http://s4f9b55a471ef4.img.gostorego...._1600x1067.jpg

Although much loved they are really hard to find now having
been discontinued 25 years ago.

Electronic gauges are a different topic on which I have
nothing positive to offer.

I was thinking of the type you show in your first reference.

Would you guess that I could check tire pressure, say 4 times, without
reducing tire pressure more then say 5 psi?
--
Cheers,

John B.

On 4/25/2014 9:09 AM, jbeattie wrote:
On Friday, April 25, 2014 5:33:22 AM UTC-7, AMuzi wrote:
On 4/25/2014 6:18 AM, John B. wrote:



(previously posted to rec.bicycles.soc by mistake)



I have a pressure gage on my tire pump but have been wondering about

whether a separate pressure gage might not be helpful. 700C 28 or 32,

presta valve, tires, at ~90 - 100 psi, and I've pumped them up

approximately every one to two weeks mainly based on the "Squeeze

Test".



I've noticed that connecting the tire pump to the tire and pumping

that the air pressure in the pump and hose rise until they overcome

the tire valve and for an instant the approximate tire pressure is

registered and sometimes if I had known the tire pressure I wouldn't

have used the pump. Thus the thought that a gage might be useful.



On the other hand, it does take a finite amount of air to operate the

gage so each time one checks the pressure it reduced the tire pressure

by some figure.





The better Bourdon tube style gauges bleed an absolute

minimum of air when checking:

http://www.yellowjersey.org/panag2.jpg


Crap, man, that tire is running at like 400 psi! (Really, though, what is the scale used by the Japanese?)

-- Jay Beattie.


Soft tire, looks about 70 psi. The rest of the world is on
the CGS system, in this case bar. One atmosphere is about
14.7psi. Your race tires run something like 7-1/2 of those.

in re CGS:
I only learned last year that kilopascals are almost but not
quite bar dammit:
http://www.wolframalpha.com/input/?i=Bar+to+KPa

Yikes! that's a mess isn't it? Makes a good defense for
furlongs and troy ounces and such.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 4/25/2014 9:15 AM, John B. wrote:
On Fri, 25 Apr 2014 07:33:22 -0500, AMuzi wrote:

On 4/25/2014 6:18 AM, John B. wrote:

(previously posted to rec.bicycles.soc by mistake)

I have a pressure gage on my tire pump but have been wondering about
whether a separate pressure gage might not be helpful. 700C 28 or 32,
presta valve, tires, at ~90 - 100 psi, and I've pumped them up
approximately every one to two weeks mainly based on the "Squeeze
Test".

I've noticed that connecting the tire pump to the tire and pumping
that the air pressure in the pump and hose rise until they overcome
the tire valve and for an instant the approximate tire pressure is
registered and sometimes if I had known the tire pressure I wouldn't
have used the pump. Thus the thought that a gage might be useful.

On the other hand, it does take a finite amount of air to operate the
gage so each time one checks the pressure it reduced the tire pressure
by some figure.


The better Bourdon tube style gauges bleed an absolute
minimum of air when checking:
http://www.yellowjersey.org/panag2.jpg

The British plunger type gauges were generally less well sealed:

http://s4f9b55a471ef4.img.gostorego...._1600x1067.jpg

Although much loved they are really hard to find now having
been discontinued 25 years ago.

Electronic gauges are a different topic on which I have
nothing positive to offer.

I was thinking of the type you show in your first reference.

Would you guess that I could check tire pressure, say 4 times, without
reducing tire pressure more then say 5 psi?


Yes, assuming you press it straight on.


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

AMuzi wrote:

:Soft tire, looks about 70 psi. The rest of the world is on
:the CGS system, in this case bar. One atmosphere is about

The cgs unit of pressure is the barye (Ba), which is a dPa. The bar
is an obsolete (but handy) unit. Most of the rest of the world uses
the SI unit, the pascal.




--
sig 123

On 4/25/2014 10:57 AM, David Scheidt wrote:
AMuzi wrote:

:Soft tire, looks about 70 psi. The rest of the world is on
:the CGS system, in this case bar. One atmosphere is about

The cgs unit of pressure is the barye (Ba), which is a dPa. The bar
is an obsolete (but handy) unit. Most of the rest of the world uses
the SI unit, the pascal.


Thanks. That's helpful.
--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

there are good reasons for PSSSSSSHHHHHHHHHHT gauging

uno - loaded touring asks for an accurate measurement relative to load and load distribution, surface, wind direction and mooooooood..

dos - subjective measurements dim with age, heat, and proximity to breakfast or sundown...biting insect swarms.

tres - tires operarated at their spec limits for exampull Conti TT used for cargo
need careful adjustment to max pressure...???...82 pounds is OK but 86 pounds blows the sidewall lightly dropping off a curb coupla inches. Blat $35...

on do we [retend to be scientific or just fill the ****er with air ?

the gauge here for SAE valves is a 900 as following. The North Koreans repson for the glove comp dweller starts off with 2 obscure and unwanted systems then goes to PSI.

I find...it necessary to hold one or two long fingers aside the 900's nose, touching the stem...this move contacts the 2 no prob.

PSHHHHHT

SUMMIT has a sale on (not so good news)

http://www.summitracing.com/search/p...flators&page=2

There's a whazzit Mieselle ? for Presta in the box. As in the UC file...

this is good as Conti Knobby and double bar tires front require some finesse. As who would know ? I imagine the bi tire big pickup low pressure Dudes are fairly xact