Bitubo HD012WMB03 wheelbase 270mm rear shock absorbers for Harley Davidson INT. /LENGTH 270MM – are ideal for Modern Classic and Custom motorcycles, thanks to the specific calibrations developed for each motorcycle model. These shock absorbers improve riding comfort and control of the motorcycle thanks to the internal hydraulic system and springs, which can be linear or progressive depending on the vehicle model. Spring preload is adjustable via a threaded ring, allowing for precise calibration of the bike’s rear suspension. The shock absorbers are single chamber and pressurized with nitrogen gas, with a floating piston to guarantee optimal performance. The shock absorber body is made of high-strength steel, while the heads are made of aluminum alloy machined with CNC machines to ensure resistance and precision. Adjustable Spring preload: Continuous.