Renewal of an old subject. Modern bikes with disc brakes have a wide variety of front forks and wheel hubs. I think the right hand mount JR counter has the best chance. The left hand counter runs backward when mounted on the right. I suppose that no accuracy is lost, but the arithmetic becomes tricky. Also many newer bikes have various do-dads on the fork ends, many associated with disc brakes. The only answer I can think of is to bring the JR counter to the bike shop when shopping. Any one have any other advice? Pete Reigel used to have photos of what worked, anyone have photos of what won't work?