The Park Tool Dummy Hub DH-1 is a versatile tool designed to replace the rear wheel of a bicycle, ensuring the chain remains in place during maintenance, cleaning, or transport. This dummy hub is particularly useful for tasks such as chain cleaning or diagnosing drivetrain issues, as it allows the bike to be pedaled and the derailleur to be shifted. Its compatibility with both quick-release and 12 mm thru axle frames makes it a valuable addition to any cyclist's toolkit. Fits seamlessly into the rear dropouts of a bicycle frame Keeps the chain secure while the rear wheel is removed Allows for pedaling and shifting during maintenance Compatible with all multi-speed and 1/8" chains Suitable for quick-release and 12 mm thru axle frames