mattr":pw32l182 said:A good rule of thumb is twice your weight in stones, +2 psi on the rear, -2 psi on the front.
Then work from that.
FWIW I run anywhere from about 14psi up to 40, depending on the tyres I'm using, where I'm riding and what I'm trying to achieve. (2.5" tyres at 14 psi have rather a lot of grip!)