Originally Posted by
wroomwroomoops
Thanks. I vaguely remember that this issue would require some special tool.
Ideally you'd use a derailleur hanger alignment tool, and for modern, higher end drivetrains it's pretty much necessary to get good shift performance, but on a kid's 1x8 you will likely get acceptable results using an adjustable wrench or similar to bend it visibly straight and adjust it. Check that the derailleur tracks parallel to the cassette. Or bring it to a shop--should be about 10-15 minutes labor. If it's really bent be aware it may break bending it back.