Motorcycle Fork Seals & Bushes

Fork tubes are kept concentric by split metal ring bushing sets on USD forks; the inner (or slide or piston) bush fits a groove at the top of your chromed inner tube, while the outer (or guide) bush fits a groove at the base of your aluminium outer tubes.
The inner bushes pair have a coating of teflon on the outside surface of the metal ring so they slide easily against the inside of the larger alloy outer tubes. The outer bushes pair have a lining of teflon on the inside surface of the metal ring so they slide easily over the hard chromed shell of the thinner inner tubes.

Dust Seals (also called wipers) are the only part you can see from the outside once the forks are rebuilt. They keep dirt and grit out of the suspension so it can't score up the chrome and wreck that smooth sliding. A quick note too - you shouldn't let mud dry on the fork tubes! No wipers are strong enough to cope and will loose little chunks. Check out our Fork Performance Parts section to find mud scrapers and tube protection covers. Pressure wash them properly when you get home from riding too!

Oil Seals are the softer viton rubber rings that go underneath that, usually featuring a tiny thin spring all around the edge to help squeeze the lip onto the inside fork tube evenly. They stop the precious lubricants leaking out and leaving metal to grind on metal. They are fragile and should be hammered home carefully during a rebuild to avoid twisting or kinking of the lips - try a fork seal driver kit.