Red Cycling Products Derailleur Hanger Alignment Gauge

Red Cycling Products measuring and straightening tool for derailleur hangers - get everything back on track again
If you're having shifting problems, it's possible your derailleur hanger was previously bent due to a fall or during transport.

With this measuring and adjusting tool from Red Cycling Products, you can determine exactly whether and to what extent the derailleur hanger is bent and accurately readjust it. This eliminates guesswork when setting up the shifting and means you'll be able to shift precisely again.