Thanks to all. This is the first set of tires I have used on this bike (bought it at 1000 miles in March, now nearing 7000). The tires on it were the OEM, now I put on Pirelli Diablo matching tires. I thought it might be too much preload, but I will also try a little more pressure in the front. I had not thought about the brake dragging, but I do not think it's happening. I like sometimes to feel the rotors after a ride, just to make sure they are not overheating from something like that, and they have been OK.
So far, after only about 200 miles, I like the Pirellis. BTW, I find changing the rear preload a pain (no room for leverage on the tool). Is there a trick to it?
Giulio