the pirellis run a rather round profile on the front and the rear falls away quite dramatically, this front causes slightly slower (by comparison to other brands) steering and makes it easier to scrub the front closer to the edge. getting to the edge on the rear requires a lot of lean and therefore more speed. with michelins, just for example, the opposite is the case, the front profile is very triangulated with a rather flat profile on the rear. this front tyre gives slightly faster steering and it's very easy to get to the edge on the rear, the front on the other hand is a different matter, i can only get near the edge of the front on a track. for what it's worth i run michelin pilot power with 35psi front and 38psi rear on the road. (30psi f&r track) cheers all.