Anti-Dive System

An anti-dive system was a fork feature on many road bikes of the 1980s. Brake pressure or caliper movement operated a valve that restricted damping oil flow in the fork, so the front end compressed less when braking hard.

The idea was to keep geometry more stable and leave more suspension travel for bumps. In practice the fork also became harsh over bumps under braking, and the systems were dropped as fork damping, spring rates and chassis design improved. Some modern suspensions, mainly BMW's Telelever and Duolever, reduce dive through their geometry instead.

If you own a bike with anti-dive units, check them for leaks and sticking. Some owners remove or disable them during a fork rebuild with a suitable kit.