Motocross/Dirt Bike Clutches

When you pull the clutch lever, you disengage your engine from the drivetrain connected via a spring-loaded clutch pack. A typical dirt bike clutch pack bathes in motor oil and consists of a series of ring-shaped drive and friction plates stacked together interchangeably. Clutch drive plates are splined to the inner hub that sits on the transmission’s input shaft. Friction plates are fitted into slots of the outer basket connected to the crankshaft. Springs push all these plates together forcing them to rotate as one. This pressure must be high enough to keep the engine connected to the transmission without slipping.

At the same time, springs don’t have to be too stiff so that the rider could disengage and modulate the clutch without putting too much pressure on the lever. During one race, the rider can pull the clutch up to 300 times, so too stiff clutch springs may lead to the rider’s fatigue. Too soft springs result in clutch slipping, which means that the power produced by the engine cannot be transferred to the rear wheel fully. Finding that happy medium is the priority for engineers designing the clutch assembly. Also, clutch slipping is the main symptom of clutch wear.

The construction of motocross/dirt bike clutches implies that when the clutch lever is partly pulled, clutch drive and friction plates have to slip. By releasing the lever slowly, you can gradually increase the pressure in the clutch pack to transfer more and more torque from the engine to the drivetrain. It allows you to start the engine more easily, gain speed from the standing stop and change gears without jerking. Depending on the circumstances, the rider can release the lever slowly or quickly ensuring better control of his or her bike’s speed. During the engagement process, pressure plate, steel clutch drive plates and friction plates rub against each other which leads to their inevitable wear.

Also, clutch springs may lose some of their initial tension. If you feel that your clutch starts to slip, emit a specific odor, or becomes too hot during its operation, it is time to replace your clutch pack and/or pressure plate and clutch springs. The replacement process is fairly simple, and you can do it at home by yourself. All that you may need for the job is right here on the digital shelves of our online store, including replacement parts and tools. It is recommended to acquire a torque wrench to tighten pressure plate bolts under the manufacturer’s specs.

We offer complete clutch rebuild kits, clutch springs, pressure plates, inner hubs, outer baskets, clutch packs, drive plates, friction plate kits, and more. Even if your clutch works fine, you can always seek improvements in transferring more power to your rear wheel, prolonging the service life of your driveline, or reducing weight by upgrading your dirt bike clutch with performance components. You can instantly feel and appreciate the effect. Don’t forget to drain the engine oil before disassembling your clutch. When changing the oil, make sure that it is formulated to work with wet dirt bike clutches. It must be labeled “MA” or “MA2".