I have only the front wheel. I ran it off and on all summer, depending on the weather and what I was doing that day. No problems, but I am not real hard on wheels - I tend to beat up derailers for some reason. And I had a mechanic relax and retension it before I put it on for the first time. The wheel is still true, and yes I see a difference in effort required when I ride, but I ride pretty fast and hard compared to some on this board (from what I can gather from posts).