Slowman wrote:
Greatzaa wrote:
Slowman wrote:
Vapor Trail wrote:
Thanks for the quick class. I've seen this calculator as well. I guess my point of confusion is the documentation on the box of Pirelli's where the pressure table was much more traditional in the numbers it listed (again, recommended 90 psi for my instance). The values obtained from these online calculators are much more appealing.
Anyone able dispel or confirm the higher pressure = sealant failure point?
i can't imagine riding a 28mm tire at 90psi, at least on the wheels i'm riding. there's a ton of volume in these newer wheels, and 60ish psi is pretty typical for 28mm tires on these wheels. or even 50ish. if you snap the tire with your finger, or press down on the tire, you'll see it's pretty hard at 60psi.
I wonder if Josh will join in this discussion. It seems the pressures on the calculator are about 10-20 psi higher than you would expect. I am on 25mm at 200lbs (rider and bike) and 90 psi is the recommendation.
that's because you're on 25mm and you're 180+ lb of pure cornfed beef. if you move to 28mm tires the pressure goes down quite a bit. if you move to wider inside bead widths on your wheels i think there's a legitimate case for the pressure going down further. if you look at the article on the front page on the new zipp wheels, and the charts therein - there's a very animated thread on this forum about this - you'll see ideal pressures are quite low.
but on those charts the 25mm tire is pumped up higher. there's between 15lb and 20lb of difference between the assumed pressure on a 25mm versus a 28mm tire.
My road bikes can't handle anything wider than 25mm....My TT bike is a Cervelo PX with the DT Swiss 1100 dicut wheels, 20mm inner rim width. Can I run 28mm tire on a wheel with internal width of 20mm?