CD-13900-Derailleur Hanger Alignment Gauge

New version! Designed to check and adjust the alignment of the rear derailleur hanger to solve most derailleur shifting problems, specifically those associated with indexed shifting systems. Tool threads into the rear derailleur hanger. Tool arm holds a gauge which marks the distance to the rim. Rotate the gauge with the wheel through an arc of 180 degrees to check potential differences. If any, apply pressure to the tool arm to realign the hanger. Head and body of the tool are CNC machined. Threaded spindle in hardened tool steel.