Good question.
Lets start with facts:
* YES lowering the PSI will result in higher temps, but not much more than 10 deg F
* The increase in temp is not enough to make a cold slick track magically give great grip.
* 1 second in faster lap time can equal 10 def F in temperature increase (depending on the track)
* Decrease in PSI will affect the handling and stability of the tire and thus the setup.
So you must ask yourself: If lowering the PSI gives more temperature and more grip, then why don't I run lower PSI all the time? (this question alone busts the myth right away)
I have observed riders lowering their PSI on cold days. I think it helps them mentally feel OK about their next session. I do not think its a major factor and is commonly very much over emphasized. If I saw someone doing it, I would not scold them. But I would not go out of my way to recommend it, and I certainly would not emphasis it as a solution to a cold track.
Thanks, makes sense.
Can I ask you one more question re wet riding? Another mith says that it's a good idea to put more air in the tyres, in an effort to keep the grooves open. The opposite being that with low air pressures (and considering that temps and pressures won't rise from riding) the 'flat spot' in contact with the track closes the grooves in the tyres. What are your thoughts on this? I can understand the logic - is there any evidence to suggest that it could be happening?
Thanks again,
Julian.
