I think it is a straight forward swap except the brake line has to be rotated to hook up to the R1 caliper. I bought one and it appears to me that the pad surface is the same as Mark II calipers although the R1 has pistons that are different diameters within the caliper. I think I'm going to stick with the original calipers since they have 4 pistons. If you have a Mark I, you should probable change to Mark II forks since the Mark Is have 2 piston calipers as I understand. I hope someone corrects me if I'm wrong.