RockShox Thruaktiv Rear Shock Damper Piston/Shaft Assembly

If you are experiencing persistent stiction, inconsistent rebound, or a 'dead' feel in your suspension that a standard air can service doesn't fix, the internal damper shaft or piston may be worn. This assembly is designed to address those internal damping issues directly.

No, this is a specific component. It is strictly compatible with the Deluxe Thruaktiv A1-B1 and the Trek Super Deluxe Thrushaft C1 models. Always verify your shock's specific model year and version before purchasing.

This kit includes the core piston and shaft assembly required for the rebuild. However, it is standard practice to replace all O-rings, glide rings, and seals during a damper service, so you should have a separate, model-specific seal kit on hand.

Replacing a damper shaft assembly requires advanced suspension service knowledge, specific tools like a shock vice and seal press, and the ability to bleed the damper circuit properly. If you aren't comfortable working with high-pressure hydraulic systems, it is best to have a professional technician perform the installation.

Yes, provided the rest of your shock body and damper housing are in good condition. Replacing these internal components eliminates the wear that causes friction and damping fade, effectively restoring the factory-fresh performance of your suspension.