Putting the first side on was a pain as well. I had to use a tire iron. I didn't know SunRingle made the CR18 in a 27" size, but it's possible i got hosed when I bought these wheels, as they were advertised as 700s. It's hard to measure exactly as they are laced up and any measurement is at an angle due to the hubs being there. I have a set of vintage Matrix Touring T unlaced that I layed against the Sun, the diff was 7mm, but if the Matrix's had a somewhat high edge, all bets are off for comparison. Anyone know a bomb proof way to measure what I have? Outer circumference?