palladio

I recently bought a tire pressure gauge made by planet bike (see attached picture). It is supposed to be usable with presta valves. Every time I try to engage it on the valve stem, a bunch of air rushes out in the process and basically deflates my tire by 10-15 psi. FYI, all my bikes have sew-ups (700x20 and 700x22) with threaded presta stems.

I figure I must be doing something wrong, but what? Before this I was using a hand pump with a gauge, but now my building has an electric pump so I need a separate gauge to check pressure before I go out.

ezdoesit

I have this Gauge and what you need to do is just quickly press it to the valve then back off if you don't your releasing all the air and your tire is deflating in of words just press it on and off and it will register the tire pressure.
I hope this helps you out and by the way I love this Gauge.

palladio

Thanks. I practiced with it some more today, but no matter how quickly I use it, I'm still losing at least 5 psi. Maybe this is just because I have such small/low volume tires? Or maybe my valve stems are a little bent and don't seal quite properly?

Well at least I'm not losing 10-15 psi anymore....