Originally Posted by
Cypress
See above.
I did. I have a hard time believing in your 33% claim. Where did that come from?
"So, how to increase the air volume? Here are few measurements:
Width Width change Air volume difference (mL) Difference 17mm rim Tyre 23–>25 144,25 15,0% 25mm tyre Rim 17 –> 19 24,04 2,2% A 2mm increase of the tyre width alone has a much higher impact (+15%) than a 2mm increase of the rim width alone (+2.2%).
And of course, the combination leads to both air volume increases, which is even better."
THE RIGHT TYRE WIDTH ON THE RIGHT RIM WIDTH - Engineerstalk : Engineerstalk
I cant see what Boyles law is supposed to prove. It only says if you inflate the bigger tyre/rim combination, with the same amount of gas, the pressure will be lower, if temperature is kept the same. Doh!
However that is not proof 72psi is adequate for a 23mm tyre. At best its an indication that IF 72psi is right for a 23mm then 62psi is also right for a 28mm.
Btw, no one disputed a bigger volume tyre "requires" less pressure, only the numbers in the chart are unusually low. Stop acting like we are all imbeciles.