I just bought a new pair of shimano R560s and a continental attack/force set to go with them. This combination is far and away the most difficult Ive ever tried to mount. Im trying to find out if its the tires or wheels are to blame or if both are contributing to my mounting woes. I finally got them on and then pinch flatted after my first ride, and havent fixed them yet. Anybody whose tried either or both of these products would be much appeciated if they'd weigh in.