Motorcycle Clutches

Some riders prefer to take their bikes to highly-skilled and experienced mechanics for service and repairs, but if you like to maintain and fix your machine with your own hands, you have to know how its main systems work. A motorcycle clutch is a mechanical assembly designed to function as a coupling between the engine and driveline. The system allows the rider to engage and disengage this link by pushing a clutch lever normally positioned over a left handlebar grip, which ensures easier starts and smooth shifting between gears. The clutch is positioned in between the engine’s crankshaft and transmission input shaft.

When the clutch lever is pulled, the crankshaft continues to spin while the transmission stops transferring rotational power to the rear wheel. When you let out the lever slowly, the inner components of the clutch assembly gradually force both shafts to spin together. The main clutch assembly consists of an outer basket connected to the engine's crankshaft via a gear train, inner basket or inner hub with splines for the connection with the transmission input shaft, clutch pack, and pressure plate. The clutch pack consists of alternating ring-shaped steel and friction plates stacked together. The pressure plate is fastened with clutch bolts over coil springs.

Friction plates are connected to the outer basket via splines, the same as plain steel plates are coupled with the inner hub. It means that when the whole clutch pack is pressed together by the pressure plate, friction forces both types of plates to rotate together. When you push the lever, you disengage the clutch via hydraulic system or cable by causing coil springs on the pressure plate to compress allowing friction plates and plain steel discs to rotate independently, which means that the crankshaft and transmission are disconnected too. As a result, the engine shaft can continue to rotate when the bike is stationary.

Also, you can switch gears smoothly by intentionally letting plates to slip thus ensuring gradual progression between engaged and disengaged states. This slipping action between friction and plain plates means that they wear over time, and sooner or later, your clutch may fail to engage fully even though the lever is all the way out. Sure, you can modify your clutch by installing stiffer clutch springs so that the pressure plate can press the sandwiched clutch pack together with greater force, but it means that you will have to press harder on the clutch lever to disengage it. If your clutch is slipping when it shouldn’t, it is time to replace your clutch pack.

To prolong the service life and efficiency of your clutch, you can choose a performance clutch kit featuring improved friction plate compound. The majority of modern bikes use wet motorcycle clutches, which means that during its operation, the clutch pack is cooled by engine oil. Thanks to this oil bath, the pack can take serious abuse. When changing your engine oil, make sure that it is labeled “MA” or “MA2”, which means that the oil is formulated to work with motorcycle’s wet clutch. On the digital shelves of our store, you can find everything that you may need to service or modify the clutch of your motorcycle.