31.8mm of durable control
Run your favorite 31.8mm clamping diameter handlebar on a bike with Knock Block with the Rhythm Comp 31.8. It adds Knock Block compatibility to a durable stem with multiple lengths to let you fine-tune the fit to your ride.

Product details
- Get 31.8mm handlebar compatibility with your Knock Block system
- Also compatible with standard headsets and spacers
- Knock Block system protects frame from impacts by fork and handlebars by eliminating over-rotation of bars
- Available in a wide range of sizes for today's mountain rider
- See Service Parts for other Knock Block parts