Harley Davidson XL 91-  883/1200  , Buell Tube frame models STM Slipper Clutch

STM slipper clutches for Harley Davidson XL 1999-  883/1200  offer two major advantages to assist the rider and help prevent damage to the engine and gearbox. The slipper clutch assists the rider by reducing the effect of engine braking. Engine braking causes the rear wheel to lock up when braking hard for a corner.

A rider that is too aggressive in this situation suffers, because the rear wheel loses contact with the ground, making continued braking and direction change much harder to accomplish. The STM clutch also helps save the engine and gearbox, again by reducing engine braking. Most motorcycle engines have a rev limiter, to stop the engine exceeding a certain speed considered safe by the manufacturer. This works fine when the engine is under power, but if a rider is approaching a corner, close to the r.p.m. red line, and then down-shifts, the engine can easily be forced to a speed it was never designed to reach, often with catastrophic results. Additional benefits are realised as the gearbox suffers less abuse for the same reasons, and it is less important for the rider to provide perfectly co-ordinated gear changes.

Material: aluminium alloys and special steel Primary spring: 125 mm Evoluzione diaphragm spring code 0S1125

Secondary spring: 85 mm Evoluzione spring code 0S2085

Basket: original HD(not included) Features: slipper system - device to control the opening - progressive engagement plate - Forced Lubrication System 3 Compatible disc pack: original HD (not included)

Tools: pressure plate mounting tool code UTL-0030 (recommended) can be found here in our shop 891505

we advice to use a Alto carbonite plate set , can be found here

and Redline Atf D4 gearbox oil

Note: when choosing the primary spring keep in mind that the greater the spring tension, the greater the pressure on the disc pack and the smaller the slipping in acceleration. When choosing the secondary spring remember that the greater the spring tension, the greater the engine brake in deceleration