Bike Multi Tools
Every MTBer needs a multitool. This is typically the first tool new riders buy, and rightfully so. In most cases, a good multi tool is all that's needed to assemble a bike. 

What to look for: 
  • Wide range of Allen/hex keys, ideally 2, 2.5, 3, 4, 5, 6, and 8mm
  • Phillip screwdriver 
  • T-25 Torx/star
  • Chain tool

Please note, these are affiliate links. 

Top Pick: Crankbrothers M17

This is what I use. It meet all the above requirements, plus four spoke wrenches, 8 & 10mm open ended wrenches, and a flat head screwdriver. It has a total of 17 tools, hence the "17" in the name.

Bonus/hack: The open side of the chain tool fits Presta valve cores perfectly. 

Runner Up: Crankbrothers M19

Same as the M17, plus two more tools: a smaller Phillips screwdriver and a smaller flathead screwdriver. I've never needed a smaller Phillips or flathead, so the extra weight/cost isn't worth it to me. 

Bonus/hack: The open side of the chain tool fits Presta valve cores perfectly. ​

​Most Compact: Crankbrothers F15

​If you're low on space or don't wear a pack, this is your best option. Slightly more expensive than the M17/19, but one the smallest multi's that includes a chain tool. The F10 is cheaper but doesn't have a chain tool. 

Budget: Crankbrothers M10

​The M10 is basically an M17 without the chain tool, which also means no open ended wrenches or spoke wrenches. If you aren't worried about chain repairs on the trail, the M10 is the best value per dollar.