25-27 psi for 2.4s
28-31 psi for 2.25s
lower rolling resistance.
lower pressure will allow the tyre to deform and flatten out giving a bigger contact patch with more grip but also with increased rolling resistance
lower pressure for off road higher on it
well there is my 2p
and i run my pressures high but then im a fatty
This debate is raging on on many a bike forum. The theory of larger contact patch sounds plausible and is widely adopted. I think real life is not so straightforward.
For one thing there are some magazines out there that actually measured rolling resistance (you guessed it, the Germans) and they have concluded lower is faster. A simple test I've read about is to see the free rolling distance from an elevated point onto flat: no pedaling, same start height, same tires, same path different pressures and see which one rolls the furthest. Probably need a few runs each for statistics. Or google the results of others who have done this already
One theory is that by deforming and conforming to the surface less energy is lost ripping the surface apart, less digging, less moving soil and gravel about. And IMHO the principle is not without boundaries, there must be a low pressure limit where the tire deforms to the point it does not work as intended. And running 2.4s also adds rotating mass to my wheels which slows me down. There must be a crossover point somewhere.
Meanwhile I just love the ride of my big tires as they have bags of grip and allow me low pressures though I'm a fatty too
Common sense was never common
28h silver rear Suntour hub
32h Ritchey champagne WCS front hub