These BMW R100 / R80 (and other R series models) YSS suspension replacement rear shock absorbers from the Ecoline range, are a high efficiency gas shock absorbers that can be adjusted according to the user. There are 2 main features to this shock: 1. It has a threaded preload adjuster which the user can turn in order to personalize their setting. 2. The shocks are completely serviceable. There is also the option to fully customise the look of your BMW R series shocks in a number of ways via our partner in Netherlands – YSS Suspension Store. Check out the options below: This shock is 420mm long and has been designed specifically for BMW Bobber / Cafe Racer conversions. Note that each shock is custom built to your specification and takes about 10 business days to process.