When I first got the pump, I filled the chamber
to exactly 120psi. The release button and the
gauge on the RockShox suspension pump makes
this easy to do to a high degree of precision.

The other day I thought I'd try it again and
I noticed it took four strokes to get it up to
120psi again!

Is this some property of the gauge?

How much psi enters the chamber for
every stroke?

Or did the seemingly (?) missing amount leave
the chamber when connecting the pump to
the valve?

Or is there a small-but-steady leak from the
chamber from normal usage?

--
underground experts united
http://user.it.uu.se/~embe8573