Shimano TL-RD11 RD Alignment

Shimano's TL-RD11 Rear End Alignment Tool lets any drivetrain doctor diagnose a bent derailleur hanger by screwing into it and measuring its relation to any point on the rear rim. Truing the hanger realigns the derailleur with the cassette, addressing what often turns out to be the frustrating, unknown source of iffy shifting and drivetrain noise.
This tool is suitable for virtually all bikes or frames with wheels from 20-29 inch. Its chrome finish adds durability and protection from corrosion on its precisely-made heat-treated carbon steel core. It is also equipped with a telescopic end for ease of use as well as more compact storage.