The BOLANY derailleur hanger extension is a unique device that offsets the position of your road derailleur to make it possible to run a wide-range mountain bike style cassette. It is an ideal solution for riders looking to convert their road, gravel, cyclocross, or commuter drivetrain bike to attain the simplicity and reduced weight of a single front chainring .
Tech Specs:Easy to install in less than 5 minutes
Material : 6061 aluminum alloy
Bike Type: Road Biycles / Mountain Bikes
Packcing included: 1pc screw
FOR Wide Ratio Cassettes
Weight :about 10g.
Application: use for rear derailleur extension, apply for 40T/42T/46T/50T mountains freewheel or 32T/36T flywheel,
to extend the flywheel speed and change it more smooth.
NOTE: Due to measured by manual, there will have1-2mm different. Hope you can understand, thanks.