If you ever bend your derailleur hanger you’ll most likely need a tool to bend it back. Most shops can charge up to $20 to fix that for you. But here’s a way you can make your own tool for a few cents.
First you’ll need a fine threaded 10mm screw from any hardware store.
All you do is remove your derailleur and thread your tool into the hanger.
From this point you can either use your hand to try and bend back the hanger…
Or you can use a box end wrench for leverage. I placed this axle nut on the screw to my wrench doesn’t slip.
Remember to be careful and not snap that hanger in half. They are designed to break apart.
This is a hanger bending tool, not a hanger alignment tool.
Commercial alignment tools measure against the wheel to ensure that your hanger is precisely in the rear wheel’s and cogs’ plane of rotation.
Correct, it is a hanger bending tool.
To convert to an alignment tool, a bar (metal, wood, plastic)with a hole could be fitted between two nuts on that axle. The wheel should be mounted, and with a ruler the distance between the rim an bar should be checked. The distance should be equal(a tolerance of few mm is OK)around the rim.