Motorcycles: Shaft vs. Chain Drive

Motorcycles traditionally use either a chain or a shaft drive to transfer power from the engine to the rear wheel. Both chain drive and shaft drive motorcycles offer their own sets of advantages and disadvantages, but chain drive motorcycles are by far the most common on the market today. A rare few motorcycles use a belt drive.

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The chain drive system is made up of two sprockets, one on the gearbox and one on the rear wheel, that are connected by a chain. In a shaft-driven system, a shaft connects a gear inside the gearbox to another gear inside a hub on the rear wheel. When the engine is sparked, power is transferred along the chain or shaft to the rear wheel, and the bike moves forward. Either system is commonly known as "final drive," as it is the last set of components employed to deliver power to the rear wheel.

Some manufacturers, notably Harley Davidson, have used belt drives on a few of their model line-ups. BMW, Kawasaki, and Suzuki have also experimented with the belt drive system.

Sports vs. Touring Drives

Classic bike enthusiasts looking to purchase their next motorcycle will primarily encounter chain drives in the vast majority of out-and-out sports bikes. But neither chain nor shaft dominates in the touring or sports touring bike market.

Of all the shaft-driven motorcycles ever produced, BMW far outweighs the competition. The company first introduced shaft drives to their models on the R32 in 1923, and since then the shaft drive has been an integral part of their touring bike line-up. The system has proven to be reliable and robust for thousands of miles. Even some of BMW's dual sport—or on-road, off-road—bikes feature shaft drives.

But BMW is the exception, not the rule. Chain drive models still far outnumber shaft drives—although belt drives are gaining in popularity. To understand why one must first understand the advantages and disadvantages of both.