 For motorcycles with chain drives, the rear axle can usually be adjusted forward and back in relation to the swingarm, to adjust chain tension, but a few models (such as some 1971/72 Triumph and BSA four-strokes and Ducati 860 GTS and Darmah 900s ) make the adjustment at the swingarm's pivot point.The hydraulic shock absorbers used on the rear suspensions of motorcycles are essentially the same as those used in other vehicle applications.Motorcycle shocks do differ slightly in that they nearly always use a coil-over spring.