Motorcycle Swingarms & Components

A swingarm is one of the main structural components of your motorcycle. Its job is to support your rear wheel keeping it firmly attached to the bike. It is called “swingarm” because it swings vertically on a pivot point allowing the suspension to carry out its function of absorbing shocks from road irregularities and damping spring oscillations. A conventional double-sided swingarm looks like a metal fork with rectangular or round arms extending from the chassis to the rear wheel axle. It has to be strong and stiff to withstand huge loads, especially if you like to do wheelies on your motorcycle.

Besides holding the weight of the bike, rider, and possible luggage, your swingarm must cope with cornering forces and twisting force produced by the final drive, whether it is a chain, belt, or shaft which transmits engine power to only one side of the rear wheel axle. The most common type of motorcycle swingarm is a swinging fork. The basic version consists of two metal rods or pipes attached to the rear axle from one end and pivot linkage on the other. Usually, a pair of shock absorbers with springs connect the rear portion of the swing arm to the seat rail.

A “cantilever” version of the swinging fork features a triangulated frame designed to be used with a single shock absorber mounted in front of the rear wheel. Some motorcycle manufacturers, such as Harley Davidson, utilize a reversed variation of a cantilever swingarm where shock absorbers remain hidden under the frame making the impression of a rigid rear suspension. In such a scheme, shocks extend on road bumps instead of being compressed. A “parallelogram” setup is usually utilized in machines with a shaft drive to reduce the counter-intuitive sensation of “shaft-jacking,” lifting of the seat when the bike accelerates. Such a swingarm looks somewhat similar to a parallelogram due to the addition of an extra link between the transmission and driveshaft.

Many drag racing enthusiasts tend to use longer swingarms or utilize extension kits to shift the center of gravity of the bike forward. It minimizes the probability of a wheelie at the start which makes the bike much easier to control. The swingarm extension kits offered in our store are a perfect solution for those who do not want to modify their swingarms permanently. They are made of strong billet aluminum and come in chrome-polished, brushed, or powder-coated black finish and feature a simple bolt-on installation. A brake hanger support is included. Note that you must acquire a longer brake line and chain or belt separately.

Some bike manufacturers equip their premium models with single-sided motorcycle swingarms. Such a swingarm links the rear wheel to the chassis from only one side (usually, the left side where the chain, belt, or shaft drive is located). A single-sided swingarm allows for much easier wheel removal and chain maintenance. In a traditional setup, to take off your wheel, first, you have to remove the axle, take the chain aside, deal with the brakes, spacers, chain carrier, and sprocket. You can forget about all that with a single-sided swingarm. You just need to unscrew the axle nut and slide off the wheel. The only drawback of a single-sided swingarm is that it must be much stronger than its double-sided counterpart. It means that it is much harder to design and manufacture, which makes it much more expensive.