Key benefits - Replaces the rear wheel on the bike for cleaning, transport and maintenance, and fixes the chain in a suitable position. An essential tool for cleaning the chain and diagnosing derailleur problems. - High compatibility with all derailleurs and 8mm chains. Suitable for quick-release and 12mm thru-axle bike frames. - Convenient and flexible. Lets the bike be shifted with the wheel removed, and the derailleur can be moved. - Easy to use. Remove the rear wheel, clamp the chain keeper dummy hub on the dropout, and keep the chain out of the way during transport or wrenching. What this tool enables - Function: Holds the chain securely while the rear wheel is removed, enabling cleaning, inspection, and maintenance without chain interference. - Compatibility: Works with all derailleurs and 8mm chains; supports quick-release and 12mm thru-axle frames. - Performance: Allows shifting and derailleur movement with the wheel removed, improving access and workflow during service. Usage scenarios - Chain cleaning and inspection: Remove the rear wheel, clamp the chain keeper dummy hub on the dropout, and clean and inspect the chain and derailleur without obstruction. - Maintenance and adjustment: With the wheel off, shift and adjust the derailleur as needed while the chain is held in place. - Transport and service: Prepare the bike for transport or shop servicing by keeping the chain out of the way and the drivetrain accessible.