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

[Emoto <emoto1@xxxxxxxxx>]

The thing about tires in the cold weather is this: In order to grip
properly, tires must come up to operating temperature. The way that
tires achieve increases in temperature is through the flexing of the
tire. The more flex, the more heat is generated. Therefore, when
riding in very cold weather, and you wish to get the same kind of grip
as you have in warm weather, you must run LESS tire pressure than you
do in the warm weather. Putting in additional pressure will cause the
tires to run even colder than the weather was going to make them run,
and will result in even less grip than if you had left them at your
standard pressure.  So, in the cold weather, either leave your tires
alone and understnad that you have slightly less grip, or reduce
pressure slightly. Adding pressure in the cold weather is just wrong.

On 11/26/05, Frederick Huganir <fredh@xxxxxxxxxxxx> wrote:
> Tom,
>
> Here's one of those things that makes me think, but I may have misunderstood
> you.
>
> I never increase PSI in cold tires to compensate for ambient temperature.  I
> only compensate for warmed-up tires by adding 10% in order to reach the
> recommended or desired cold tire PSI.  I apply this to car and bike tires.
> The way I've seen it, the density of all cold air isn't the issue, but
> rather, the relative density between the air inside and outside the tire,
> regardless of temperature.  Am I out in left field?
>
> Thanks.
>
> I wish I was heading down that way!
>
> Fred
>
>
> ----- Original Message -----
> > seat.  Tires inflated 5 pounds over to compensate for the cold temps
> outside
> > my garage.
>


- --
Bob

                      Eventual Master of the Obvious
        R1200GS CB750F DoD EMOTO BMWMOA SOHC4
Such a long, long time to be gone, and a short time to be there...

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