How accurate is the gauge on your pump?

Recently I purchased a new floor pump. I then noticed many tyres seemed to be "a bit low". On checking I found a variation of 15psi over the 3 pumps.

This may not be a big problem at the high (140psi+) end. However for comfort and mountain bikes with 30-50psi tyres this can result in gross over or under inflation.

I suggest finding an accurate gauge and calibrating your pumps. I have an old Schrader Valve that fits between two pump heads at the same time so I can compare the two gauges.

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Cheers,
George.

I think a good digital gauge is a good investment. I have a Topeak and it cost about $17-18 here in the USA. My floor pump is fairly accurate but still about 3 or 4 lbs over. With proper inflation you can regulate how the ride feels. With just a few pounds less you can make a stiff bike comfortable. Also most people over inflate their tires and less inflation gives longer tire life.

Digital or analogue, a gauge is only as accurate as its calibration. There are quality as well as cheap gauges in both camps.

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Morphed Bianchi Camaleonte IV 2006, Ridley Damocles 2006, Garmin, Mac

I have one Topeak pump whose guage is pretty accurate, plus or minus 2 PSI. I always use a good quality handheld guage though. Most pump guages can be pretty far off.

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One life, one chance. Don't waste it!

When I remove the pump hose from the tire valve, there is always a small escape of air from the tire.

How can the reading be accurate if it is made before that air escapes?

Do you overinflate in order to have the right pressure and account for this air loss?

That is why I use my digital Topeak gauge after using the pump. After taking the gauge off there is also a loss of air ,which if I am carefull, is about half a pound of pressure. I came to this conclusion by taking successive readings.