All dependent on rider weight and has a lot to do with the course you are riding. I weigh 85 kilo's and run 2bar front and 2.1bar rear. You'd hate to go too low and end up losing tires... http://cdn.coresites.factorymedia.com/mpora_new/wp-content/uploads/2014/06/Aaron-Gwin-Tyre-Flat.jpg