Motorcycle Fork Compression Piston Base Towers

If your motorbike has modern "Separate Function Forks", you probably have a comp adjustment clicker on one top cap & reb on the other, but for many adjustable designs both caps have compression damping adjusters - learn more about open or closed chamber front forks. If you've never adjusted your dampers, read our clickers article - they're like opening or closing a tap for more or less suspension oil to flow.

Adjuster assemblies are compact but complex, with a top cap sealed against the fork tube with an o-ring, a clicker assembly & bleed screw inside, and threaded hollow centre rod screwed underneath.

At the bottom end are the comp valving parts locked onto one of these base valve posts - the specific set of shims & washers assembled either side of the damping piston are held onto the "tower" using a locknut.

A connecting push rods slides inside the centre shaft, pressing harder or softer on the valves depending on your clicker adjustments, compressing or loosening the stack.

A free piston slides up & down the centre shaft, with inner & outer seals plus bushes to prevent oil getting past. An Inner Chamber Spring presses between the cap & the sliding piston - helping set the initial fork plushness - so changing how strong the ICS is will make the forks feel softer or firmer at the beginning of the stroke.

If you can't find what you are after, we have a collection of small clicker parts in our Fork Adjuster Parts category - plus we have some great aftermarket parts for comp assemblies like clicker knobs and super strong billet alloy free pistons. For people looking to tune beyond the OEM valving we carry revalving kits to push your performance to the next level!