How did I live w/o this tool for so long?

I've been a garage hack mechanic for many years. And I even got some shop type tools such as a headset press and cup removers recently (and I am amazed how often I have actually used them too). But one tool that I just got I cannot fathom how in the world I got by w/o it.

The Park DAG-1 derailleur alignment gauge.


My FS XC bike has been having shifting problems and it just looked like a bent hanger. I tried the crescent wrench technique and it didn't do much so I finally got wise and bought this. OMG that hangers was off by so much. Tweaked it and shifting is spot on. Just for kicks I figured I'd check my hardtail. It wasn't shifting badly or anything but it too was off by a significant amount. I tweaked it with the tool and shifting was noticeably better.

I can't imagine how much time I've wasted chasing around shifting problems that were most likely caused by a hanger that was misaligned.

IMHO this tool should be on the top of your list after allen wrenches and a chain tool, especially for a mountain biker who ride technical terrain where rocks/roots can tweak your hanger in a heartbeat.