Originally Posted by
Cypress
Math. A 23mm tire will "open up" to 26mm on a wide rim. Larger diameter tire plus larger rim chamber = significantly more volume than you would think. If we treat the tire like a perfect cylinder and forget the added volume of the rim chamber (which adds to the percentage), the tire alone sees a 28% increase in volume.
23mm tire in a perfect cylinder: (2097mm ((pi)((11.5)^2))) 871,252 ml
26mm now because of the wide rim: (2110mm ((pi)((13)^2))) = 1,120,261 ml
And on a wide rim with more V O L U M E that a narrow rim, it is unequivocal, indisputable, and absolute proof. But again, you seem to be missing that point completely....still.
.
The disconnect in this conversation is that while everyone agrees that wider tires need less PSI, some wheel makers seem to go way too far in their reduction. IOW, 72psi wouldn't be correct for a 26mm tire either.
Here's Schwalbe's recommended inflation chart. Who's right and who's wrong and what supports this?
