Item # SHI00BN
Shimano TL-RD11 Derailleur Hanger Alignment Tool $252.00
Screw and true.
Sometimes cassette chatter isn't the result of compressed housing or an out-of-tune derailleur. Shimano's TL-RD11 Derailleur Hanger 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.