PLEASE NOTE: This is a special order product from Bonamici Racing with a 30-45 day manufacturing lead time.

The Bonamici Racing Chain Adjuster has been developed exclusively for track and racing use on Yamaha YZF-R9 bikes fitted with the Yamaha Tracer 9 / XSR900 swingarm conversion, using OEM swingarm code B5U221100000.

This specialist racing solution has been engineered for teams and riders using the longer Tracer 9 / XSR900 swingarm configuration to enhance the YZF-R9’s on-track performance. Designed specifically around this swingarm geometry, the system delivers the precision, strength, and serviceability required in demanding racing environments.

A special quick-removal axle system allows for fast and efficient wheel changes during race use, while the high-quality construction and precision machining ensure excellent durability and accuracy.

• Designed specifically for Yamaha YZF-R9 racing applications
• Requires Yamaha Tracer 9 / XSR900 swingarm conversion
• Developed for swingarm OEM code B5U221100000
• Intended exclusively for track and racing use
• Special quick-removal axle system for fast wheel changes
• Axle CNC-machined from solid 39NiCrMo3 steel
• Internal hole lapping process for maximum precision
• Durable phosphating surface treatment
• M24x1.5 thread specification
• Recessed hex socket on the axle head for quick tightening and removal using an Allen key insert
• Left side designed for axle insertion
• Right side adjuster features M24x1.5 threading for direct axle fastening without a separate nut
• Right side equipped with dedicated support for the Yamaha YZF-R9 rear brake caliper
• Compatible exclusively with original Yamaha YZF-R9 rear brake calipers

Important Fitment Note: This product is designed for Yamaha YZF-R9 bikes using the Yamaha Tracer 9 / XSR900 swingarm conversion only. It is not designed for the Yamaha MT-09 swingarm.

Bike Fitment:

Yamaha YZF R9 2025-