I rode a pair of Gipiemme 650's and hated them for one reason....It was almost impossible to change the tire! They were not a standard size and it took 30 minutes and I wasted 2 tires trying to force them on. At $60/tire, I decided new wheels were a cheaper option. I never couldv'e changed a flat during a race on them....and they were supposed to by my race wheels.