Re: Or..... (or PSI and temperature)

["Frederick Huganir" <fredh@xxxxxxxxxxxx>]

Sorry that I was not clear.  I suppose I touched on two issues.

First, that a decrease in outside ambient temperature ("it's cold outside")
does NOT require us to inflate tires to a higher PSI.  PSI is the relative
air pressures between air outside the tire and air inside the tire.  When I
go out to the garage on a very cold day, I may find the PSI has dropped, but
I only add air to bring it up to my standard.PSI without regard to how cold
it is.  Now, some list members are adding the concept of DECREASING
inflation when it is cold outside in order to speed the warm-up of tires.
My question to that is, should tires be brought up to normal PSI after
warm-up of tires, so one is not riding on warmed-up but underinflated tires?
If so, plan on an air stop, or carry an air pump!

Second, I mentioned in passing that the only time I increase inflation based
on temperature is when I am checking PSI on warmed-up tires.  The reason for
this is that PSI is supposed to be gauged on cold tires, and warm-up is
calculated in recommended PSI.  The simplest calculation is to add 10%.
Based on what I've known (at least up 'til now), I would apply the 10% rule
for warmed-up tires even in very cold weather.

I am going riding in a few minutes, and it's climbing to 40 degrees here in
south-central Pennsylvania, but at least the roads are dry.

Fred

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