Swingarms can be single or double sided, and have appeared in a variety of geometries. Many single-sided also incorporate the driveshaft.
Swinging fork - the original version consisting of a pair of parallel pipes holding the rear axle at one end and pivoting at the other. A pair of
shock absorbers are mounted just before the rear axle and attached to the frame, below the seat rail.
Cantilever - An extension of the swinging fork where a triangulated frame transfers swingarm movement to compress shock absorber/s generally mounted in front of the swingarm. The HRD-
Vincent Motorcycle is a famous early form of this type of swingarm, though
Matchless used it earlier, and
Yamaha subsequently. The
Harley-Davidson Softail is another form of this swingarm, though working in reverse, with the shock absorbers being extended rather than compressed.
Parallelogram - Was first introduced commercially in 1985 on the Magni "Le Mans". Magni called the system
Parallelogrammo. Various parallelogram systems have been developed by other manufacturers. Whereas downward generated mechanical forces would cause a chain-driven bike to
"squat" at the rear under acceleration, the torque reaction of a shaft drive machine would induce the opposite, causing the seat (and rider) to rise upwards, a phenomenon known as
"shaft-jacking". This anti-intuitive sensation can be disconcerting to riders, which parallelogram suspensions seek to neutralize. BMW introduced its
Paralever system on its 1988 R80GS and R100GS motorcycles, which adds a second link between the rear drive and transmission to allow the driveshaft to pivot along the same axis as the sprung rear frame.
Moto Guzzi patented its
Compact Reactive Drive Shaft system (Ca.R.C.), where the driveshaft is free to float into its structure, providing much softer feedback from transmission. An upper arm serves as a guide to close the geometry of the suspension.
Extended swingarms - are often used by
drag racing motorcycles (called dragbikes) to keep their
center of gravity as forward as possible, which reduces the tendency to
wheelie at the start.
Single-sided swingarm - a suspension lying along only one side of the rear wheel, allowing it to be mounted to a hub like a car wheel. Also found on
scooters, where a robust chain case doubles as the swingarm linking the engine and rear wheel, single-sided swingarms need to be much stiffer and more heavily built than double-sided, to accommodate the extra torsional forces. Having a single mounting point guarantees proper wheel alignment. Single-sided swingarms date from at least the late 1940s. In 1948, the
Imme R100 produced by
Norbert Riedel of Germany had both a single-sided front wheel suspension as well as a single-sided rear swingarm that doubled as the exhaust pipe. In 1950 Moto Guzzi introduced the Galletto, a large-wheel step-through scooter. In 1980,
BMW introduced its first single-sided swingarm on the
R80G/S, the "Mono-lever", which was superseded by the "Para-lever" used currently.
Honda currently features this style of swingarm on the
Honda VFR.
Ducati has created several models featuring single swingarms, most notably the
Massimo Tamburini-designed
916 series. While Ducati abandoned this style for the
999, the company returned to it for the
1098 superbike in 2007, and it survives in the current
Ducati 1199. The
Triumph Sprint ST and
Speed Triple also feature single-sided swingarms.
Images File:Lambretta Model C 123cc 2 swingarm closeup.JPG|alt=The image shows the starboard side (right side when facing forward) of the suspension of a Lambretta Model C. The swingarm, spring/damper unit, and wheel are shown. |Right side Of a Lambretta Model C, showing swingarm and suspension. File:Lambretta Model D 123cc - close-up of rear wheel - 20080302.jpg|alt=The image shows the port side (left side when facing forward) of a Lambretta Model C. The wheel and the lug nut are visible but there is no visible connection between the wheel and the rest of the scooter.|Left side, showing rear wheel with no visible suspension. File:SprintST.jpg|
Triumph Sprint ST with single-sided swingarm. ==Squat and shaft-jacking==