Motorcycle Shock Seal Case Assembly

Motorbike shocks use a damping shaft that slides inside the main shock absorber body. To keep all the oil and nitrogen pressure inside that casing there is a lower seal head assembly between the two.

Rear dampers have multiple defences in there - an oil seal deep inside, a dust wiper on the outside, a rod bushing to keep it sliding concentrically, a rubber o-ring sealing the outer diameter and a rebound top out bumper facing inwards. That bump stop can be a rubber ring or a small steel coil spring, and it makes sure no damage happens if the shock piston bumps into the bottom case (like when you jump the bike).

These are pre-assembled shock lower body cases - factory motorcycle suspensions like KYB & Showa, as well as reputable aftermarket options like SKF and All Balls.