You might have heard about the Assist Slipper Clutch (ASC) also known as slider clutch or back-torque limiter, while talking about the performance motorcycles. It comes with almost every high, mid and some entry-level performance machines. The technology allows quick down-shifting even at the high speed, without wheel locking. Let's see that how it helps the rider and its working.
A rider needs to downshift gears at high speed mostly at the time of cornering. Sometimes, the clutch remains engaged while performing the action and the rear wheel suddenly locks for a while resulting in the loss of traction. This loss ot traction can turn into an unexpected skid causing a major accident. In this situation, Assist Slipper Clutch can help you to perform the action safely.
The ASC consists of two types of cams, an assist cam and a slipper cam, which allows to drive the clutch hub and operating plate together or apart. In normal situations, the hub and the plates work together like a common clutch assembly. When the system feels excessive engine braking due to quick downshifts, the slipper cam comes into action and differ the forces on the hub and the clutch plates. It relieves the pressure on the clutch plates and allow them to slip. The clutch remains disengaged until the transmission gear matches speed of the engine.
The mechanism prevents the sudden wheel locking due to downshifts and the rider can perform the action aggressively without loosing the traction on the rear wheel. The system was specially developed for the racing machines and it is like a boon for sport and track riding. Today, it comes with the most of supersport styled motorcycles from the high end Suzuki Hayabusa (GSX-R1300) to the entry-level Kawasaki Ninja 300. The latest KTM RC 390 is also expected to get this feature by the end of 2015.