FAST FACTS

1 Sigma slipper clutches use airframe quality aluminium to make their clutches, as this guarantees the best compromise on weight and strength.

2 If you’re wondering whether your slipper clutch is functioning properly, you should test it in every gear in a safe environment, such as a race track. On releasing the clutch, the rear wheel should refrain from locking up and the revs should not be fluctuating excessively as the engine and wheel speeds are matched by the clutch. Also, feel for the regular pulsing on the clutch lever, as this is a positive sign that things are working as they should be.

3 MotoGP clutches will probably only last two or three races, while the actual plates and springs will need changing after every session.

4 Every slipper clutch design is unique to the bike it’s fitted in. There are some common crossover parts, but every slipper clutch has to be crafted and honed to achieve the right fitment and characteristics required.

5 To cope with extreme power outputs, such as that from 400bhp turbo tuned Hayabusas and the like, conventional slipper clutches simply aren’t up for the job. This means that special slipper clutches have to be produced, featuring extra plates and springs, as well as a much more heavy duty basket. Otherwise, the sheer power would destroy the unit on application.