Originally Posted by
raceboy
Minimal effect. When I raced shifter karts, tire psi would only elevate 2-3 psi during a race. And you could barely touch the surface of the tire after a race because the soft rubber was hot and gooey. Bike tires don’t generate high heat like that.
Test it out. Check your psi before a high speed descent. Check them again at the bottom of the descent to measure the difference.
Unless there's some special setup.. the simple act of checking tire pressure will usually remove a few psi from the tire.. so if you're doing this measurement and finding the tire a few psi higher than you started, in actuality before you checked it could have been 6-8psi higher.