There are a handful of tools that a mountain biker should have in their possession. But there’s one tool that not many people have, but its something you all NEED.
It’s the Park Tool DAG-2
I bought this tool online for around $50. You may think, that its a bit steep to pay for one tool, but it actually pays for itself within a few uses. You see, a shop will charge you as much as $25 to align your hanger. It is an intimidating tool to look at (that’s what she said), but its pretty easy to use. Here’s a video that best explains how to work with the tool.