General Cycling Discussion - Tire Gauges

What tire gauge does everyone carry around with them that works?

I don't carry it unless I'm touring, but I found a nice presta valve metal one at my local bike shop. It was that or the Zefal, which is lighter and takes both presta/schraeder.

Been thinking of trying a couple of these.

http://www.thetyrepressuremonitor.com/products.asp

Or for those in the US,

http://www.derbycycles.com/cgi-bin/eShop/index.cgi?pid=1500

Zefal Twin Graph

I have two of the black plastic Zefal gauges that agree with each other and seem to work fine after a couple of years.......they also agree witht he gauge on my tire pump...that may not mean much....Lime bekologist, I only carry it on tour....my roadies use CO2 and I take what the cylinder shoots.

My thumb. After I pump my tires up at home, I press on the center of the thread firmly with my thumb. I'm pumping one bike or another four or five times per week. After using your thumb at home four or five times a week, you develop a VERY accurate feel for the correct PSI. You will easily be able to get within 10 PSI of your "home" PSI setting by just using your thumb.

The ideal PSI for any given tire is directly related to the weight of each rider. When you put your full weight onto the bike, you should see the rear rim move downwards very slightly...about 1/8th of an inch. If placing your full weight on the bike results in ZERO sag of the rear rim, your PSI is too high. But, if your weight causes a substantial sag...the rim moves half an inch toward the pavement, then the PSI is much too low.

Same here......my thumb is my pressure gauge.

..my thumb has a hard time remembering what 65 in a 26x2.125 or the 45 in the balloon tires is versus 120 in a 700x23 and the 75 in the 700x37s so I use the gauge to make sure my thumb is still calibrated for roadside checks!

Black plastic Zefal and G H Meiser & Co. Accu-gage. They agree pretty well with each other. I've noticed that the Zefal will hold the pressure reading for weeks after it is used if I don't zero it, but the pressure in the Meiser will gradually leak away within a few minutes of taking the reading.

- Wil

..my thumb has a hard time remembering what 65 in a 26x2.125 or the 45 in the balloon tires is versus 120 in a 700x23 and the 75 in the 700x37s so I use the gauge to make sure my thumb is still calibrated for roadside checks!

With slick tires, your thumb will be surprisely accurate with ANY size tire. With knobby tires, it is more difficult to get a feel of tire deflection.


The reason thumb pressure can work well is that the ideal pressure for any tire is the pressure that will very slightly deflect under the rider's weight. When a 200 pound rider gets onto the saddle, that puts about 110 pounds of weight onto the rear tires. The "perfect" PSI is the PSI level that just allows his rim to "sag" about 1/16th of an inch, or 1/8th inch toward the pavement under load.

When you place your finders around the rim, place the widest part of your thumb on the tire, and press with ALL of your strength, you are placing around 90 to 120 pounds of pressure on the tire (depending on your hand size and hand strength). So, when there is a barely detectable amount of deflection, the PSI is in the "ideal" range.

I have a bike where the "measured" ideal pressure is just 30 PSI. A mountain bike were the "ideal" is 60 PSI. Road bikes where the "ideal" is around 100 PSI. The thumb test works on all three types of tires. When the super fat beach cruiser tire just SLIGHTLY deflects under thumb pressure, it is at 30 PSI. When the 25mm road tire just slightly deflects, it is at 100 PSI.

The ultimate test is when you put your weight on the saddle. If the rims deflect about 1/16th of an inch down toward the pavement, your PSI is perfect. No gauge needed.

..my thumb has a hard time remembering what 65 in a 26x2.125 or the 45 in the balloon tires is versus 120 in a 700x23 and the 75 in the 700x37s so I use the gauge to make sure my thumb is still calibrated for roadside checks!Even if my thumb is off by a few PSI's, it is no worse than my three pressure gauges which constantly give different readings. :)

I have a black plastic Zefal, I never use it now because it gives the same reading as the guages on my son's Joe Blow and my floor pump.

Zefal Twin Graph

Ditto. I've had one for ~10 years or more. Still works, dead accurate. Cheap too. Bought two more this year so I can keep 'em where I'll use 'em.