Originally Posted by
Velocivixen
@
fender1- wondering how roller cams limit size? How is it more time consuming? I have roller cams so I want to know for future reference. I know on some bikes I have to let the air out of my tire to get the wheels off to clear brakes. If adjusted well the cam can easily be removed from the rollers so as to open the caliper arms to remove wheel. Am I missing something? As to your original question, I don't know.
Depending on the position of the roller cam plate and the curvature of the arms, the wider/ higher profile tires seen today (2.3" +) might rub against the cam or the brake arms. back in the day, there weren't very many high profile, fatter MTB tires on the market, save for the 2.2" Specialized Hardpack.
One way to set the Cam up in order to release the brake, and get the wheel out without deflating the tire is to set up the Cam just loose enough to remove by hand, then take up the cable slack by using the adjusting barrel on the brake lever.
Not as easy as having a brake QR; one of the things that made the Shimano U-brake more user friendly.