The Lainer Suspension Free Piston kit is designed for front forks using the SHOWA SFF AIR system. It is intended as a replacement for the stock free piston when servicing air forks, particularly where bleeding is difficult or the original plastic piston is compromised. Supplied with associated service parts, it supports a complete refresh of the free piston assembly.

Inside the System

In a SHOWA SFF AIR fork, the free piston plays a key role in separating internal volumes and managing pressure behaviour inside the cartridge. If the piston is damaged or not sealing correctly, bleeding can become difficult and fork function can become inconsistent. This kit is described as addressing those service issues by improving cartridge bleed and supporting more consistent hydraulic pressure management.

Serviceability

Replace the free piston during a fork service if the original piston shows wear, cracking/breakage, deformation, or if you are chasing persistent bleed issues after correct workshop procedure. It may also be appropriate when rebuilding a fork with known pressure-related faults in the cartridge. If the existing piston is in good condition, the fork is bleeding correctly, and the sealing surfaces are undamaged, replacement may not be necessary as part of routine maintenance.

Key Features

  • Free piston kit for front forks with SHOWA SFF AIR
  • Developed to replace the stock free piston described as hard to bleed
  • Supplied with bushings, O-ring and oil seals
  • Designed and made in Italy by Lainer Suspension Racing

Compatibility

  • CRF 250 (2015–2017)
  • KXF 450 (2015–2016)
  • RMZ 450 (2015–2016)

Setup & Workshop Notes

This is a workshop-installed internal fork part. Follow the correct SHOWA SFF AIR service procedure for disassembly, bleeding and seal handling, and inspect mating surfaces for damage before reassembly. Replace sealing elements included in the kit where required during installation to maintain proper sealing and pressure behaviour.

SKU SHOWA_FREE_PIST_40X12_AI
Brand Lainer Suspension
Shipping Weight 0.0500kg
Shipping Size 0.050 x 0.050 x 0.050m
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