Originally Posted by
DaveSSS
I just happen to own several brand new, high quality liquid filled pressure gages that eventually will get used for monitoring water pressure in a large irrigation system. I made a manifold with two of those gages and a presta valve mounted to it, so I could use my 30+ year old Silca pump to pressurize the manifold. My two new gauges agreed within 2 psi at 80, but my old pump gage registered about 8 psi higher, so it's reasonable to assume the the old gauge was not accurate. I did another check, with a third gauge and got an even closer agreement. The 6 bar or 88 psi mark is now my reference for 80. I always use my pump gauge to measure tire pressure, when I top them off, before a ride.
The Winters brand gauges that I have seem to be well made and you can get a 0-100 or 0-160 psi range. I have one of each. Winters claims plus or minus 1.5% accuracy, while some cheaper gages are plus or minus 3%.
https://www.amazon.com/Winters-Stain...1856497&sr=8-3
I used to work in heavy metal fabrication. Extensive machining. I also set up gauge rotation and calibration systems for multiple plants. My experience there showed me that the vast majority of gauges in use every day are wildly out of calibration and weren't even close on day one.
At one point I decided to start getting an idea of how far off all the different pumps and inflators I used in the shop were when compared to a calibrated gauge I had around for specific work. I saw variances of +-20psi.
This is why I always tend to blow up on threads where people sit and try and argue that someone else is using the "wrong" pressure because it is 5 psi or less off of what they believe they should run. Pressure discussions without a basic understanding of our lack of ability to read accurate pressures is kind of pointless.
This is again why I posted way up above how I stopped giving pressure numbers as advice at races. I simply ask what they have been running and offer advice on which direction and how far to move that number...knowing full well they will use the same technique and pump they always use.
I have watched mechanics and riders argue about 2 psi at UCI races when they are using different gauges. Always makes me laugh. Then I have watched Katie Compton run in and tell Mark how to change pressure within 1 psi and known they are actually dialed and correct.
Pressure discussion in here are kinda pointless IMHO