On 06/09/2017 2:59 PM, Jeff Liebermann wrote:
On Wed, 6 Sep 2017 11:02:12 -0700 (PDT), Doug Landau
wrote:

Quantity is my substitute for quality.

So, to know the exact pressure at which his tires are
inflated, Tom should own a dozen guages, apply
them all, and average the results?

Sure. The errors tend to random, some high, some low, some large,
some small, etc. When a large number of measurements are averaged,
the result tends to be fairly close to reality. At least that's what
some climate researchers claimed when they averaged the results of
many prehistoric temperature and CO2 proxies, each of which were
suspected of being inaccurate, and produced an average which the was
declared accurate.

Actually, it would be more interesting if we took pressure readings at
various times of the day. If you set your tire pressure to some
number on a cold morning, and then go for a ride in the hot sun, your
tire pressure will increase. Strictly speaking, one needs to be
seated on the bicycle in order to get an accurate measurement or
proper setting. That might be a bit awkward unless you're a
contortionist. It might be instructive (and amusing) to attach a
BlueGoof wireless tire pressure gauge and data logger to a wheel and
watch the variations in pressure as the bicycle bounces down the road
or does aerobatics. I suspect that you'll find large variations,
which should make you wonder why anyone bothers to set the tire
pressure more accurately than hard, firm, mush, soft, and flat.

Math, numbers, formulas, and calculations:
http://www.velonews.com/2017/03/bikes-and-tech/technical-faq-science-tire-pressure-rim-width-heat-buildup_433214
Math hates me.



Or just buy a decent pump and forget about it.