Single sided swingarm
A single-sided swingarm is a type of motorcycle swingarm. As its name implies, it lies along only one side of the motorcycle's rear wheel, rather than the conventional swingarm which support the rear axle on both ends. It allows the rear wheel to be mounted like those of an automobile. This makes wheel maintenance simpler since removal involves the loosening of a set of lugs or a single nut, sliding the wheel forward to slacken and uncouple the drivechain (when fitted with chain or belt drive), and then pulling out the axle shaft. When made with an S-shaped contour, these swingarms need to be much stiffer than the double-sided versions to accommodate the new torsional forces incurred by holding onto the wheel by just one side. Having a single mounting point also guarantees proper wheel alignment. The single-sided swingarm are also found on small machines where a robust chain case acts as the swingarm connecting engine and rear wheel.
Single-sided swingarms date from at least the late 1940s being used on the 1949 Imme R100 and the 1950 Moto Guzzi Galetto. Honda currently features this style of swingarm on the VFR Interceptor. Ducati has created several models featuring these swingarms, most notably the Massimo Tamburini-designed 916 series. While they abandoned this style for the 999, they returned to it for the 1098 superbike in 2007, and it survives in the current 1198. BMW has long been an advocate and many BMW designs incorporate shaft-drive rather than chain drive. Triumph also features motorcycles incorporating a single-sided swingarm.
The quest for additional performance through weight reduction has seen the departure of the centerstand that can be used to raise the rear wheel off the ground. Lacking this built-in facility, quick rear wheel removal becomes moot without a separate wheel stand. However, BMW and Honda still utilize center stands on their single-sided swingarm models.