Motorcycle Suspension Compression Valve Stopper Cup

Compression Valve Stopper Cup

Your motorcycle front fork has a thick metal disc with machined passages between both flat sides, the piston or valve. Stacked on one or both sides of this piston are the valving shims, and the height and permissible deflection is set by the stop washers. Compression valve stopper cups (base stop washers) prevent excessive shim deflection and permanent damage from exceeding the elastic limit. The piston and its shim stacks are secured with a locknut, sealed with o-rings and PTFE bands or soft PTFE bands. We also sell complete shock pistons. For tuning reference see our shim equivalence calculator, suspension budget guide and rebuild video links.

Protects shim stacks and controls damping

  • Prevents permanent shim deformation by limiting deflection
  • Maintains intended oil flow through compression and rebound stacks
  • Available in multiple diameters and thicknesses to match pistons
  • Essential for accurate revalving and longer shim life

Recommended Pairings

Consider matching stopper cups with Suspension Tools when rebuilding or revalving.

Shop Compression Valve Stopper Cup

Browse our range of base stop washers and related piston components to protect and tune your forks.

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Compression Valve Stopper Cup

Your motorcycle front fork has a thick metal disc with machined passages between both flat sides, the piston or valve. Stacked on one or both sides of this piston are the valving shims, and the height and permissible deflection is set by the stop washers. Compression valve stopper cups (base stop washers) prevent excessive shim deflection and permanent damage from exceeding the elastic limit. The piston and its shim stacks are secured with a locknut, sealed with o-rings and PTFE bands or soft PTFE bands. We also sell complete shock pistons. For tuning reference see our shim equivalence calculator, suspension budget guide and rebuild video links.

Protects shim stacks and controls damping

  • Prevents permanent shim deformation by limiting deflection
  • Maintains intended oil flow through compression and rebound stacks
  • Available in multiple diameters and thicknesses to match pistons
  • Essential for accurate revalving and longer shim life

Recommended Pairings

Consider matching stopper cups with Suspension Tools when rebuilding or revalving.

Shop Compression Valve Stopper Cup

Browse our range of base stop washers and related piston components to protect and tune your forks.