Bicycle mechanic review of Crankbrothers M20 multi-tool

Crankbrothers M20 Multi-Tool Review

Full review of one of the greatest bicycle multi-tools on the market.

Disclosure: Some of the links below are affiliate links. This means that, at zero cost to you, I will earn an affiliate commission if you click through the link and finalise a purchase.

Good Bits

  • Solid 
  • Compact
  • Good chain tool
  • Good selection of tools

Bad Bits

  • Tool bits prone to rust.
  • Some QC defects reported in valve core and rotor straightener tool. 
  • Chain breaker deflecting under heavy load

Who are Crankbrothers?


Crankbrothers was founded in 1997 from a garage in Laguna Beach US by Carl Winefordner and Frank Hermansen. Their first product was the “speed lever” after which they released the “power pump” and some mini tools. They specialise in pedals, wheels, dropper posts, pumps, tools and accessories. Their products and brand have become recognised globally and they produce some of the finest bike mini tools on the market.

The M20 is the largest multi-tool in their line up measuring 8.9×5.4×2.6cm with the snap on case and the tool weighs in at a fairly hefty 203g. There is a small range of colours available for the outer body sections, gold, Matt black/red, matte black and nickel.

What does the Crankbrothers M20 multi-tool look like?


The tool construction is similar to most others in its class using a hard anodised outer body piece with a Matt finish, there is also knurled portion of the outer body piece to aid with grip when the tool is in use. The bits all have loops on the end through which a bolt is inserted and tightened to keep the tool together. The bolt holding the tool together can be tightened or slackened to increase or decrease the friction force when moving the tool into or out of position.

As mentioned earlier the tool has a plastic case that clip onto the body of the tool, the case contains the spare tyre plugs but also has moulded portions to hold spare links for your chain.

The tool has 20 high tensile Cr-V bits including the clip on case and some integrated tools.

What functions does it have?


The full range of tools is as follows:

  • Chain tool: 8/9/10/11/12 speed compatible 
  • Hex keys: #2/2.5/3/4/5/6/8
  • Torx: T10/T25
  • Open wrench 8mm
  • Spoke wrench #0/1/2
  • Philips screwdriver: #1/#2
  • Flathead screwdriver: #1
  • Tyre plug tool
  • Tyre plugs
  • Valve core remover
  • Rotor straightener

Public opinions


Research for customer feedback was generally very positive and the vibe was that it is a great quality tool from a well known and establish brand. There were a very small number of complaints about the tool bits being prone to rust. The bits appear to be plated for corrosion protection so this complaint could indicate the plating easily chips off or the person somehow damaged it during use. There was only two complaints I could find relating to this issue so I wouldn’t expect it to be common for every product.

Another complaint I found was relating to an excess of material on the valve core and rotor straightener, the person explained how they had to file it down to fit. The problem with reviews is that you never get a full story of the situation, this was just one review so a large pinch of salt is needed.

A further report i found was the chain breaker tool deflected under heavy load, this could indicate a bit of a weakness in design but is more likely that the person either hadn’t set the tool up correctly or their chain was overly dirty.

Final thoughts?


I love the functional, no nonsense styling with subtle colour accents to give it a bit of identity. It’s not the lightest tool in the line up but that’s not a bad thing because that extra weight has gone into make bits that look like they can handle more torque. It’s a chunky tool, which some may not like, you know when it’s in your pocket! But this can play to its advantage in offering superior grip during use.

The selection of bits on this tool are excellent they would cover most bike needs, I love the tyre plug tool for tubeless riders and a big thing for me is the 8mm hex bit is not a socket that is detachable and can get lost. My only gripes would be that the spoke wrench may not offer as many sizes as others and there is only one open wrench size but these are hardly show stoppers.

I have mixed feelings about the detachable case with the tyre plugs in it, one one hand it’s neat, provide storage for chain link items and you can remove it when using the tool. On the other hand I can’t help but think if you drop the tool the clips cold snap off making the case useless, this is only a thought though I haven’t heard of this happening.

Lastly, this tool doesn’t come with a storage case or pouch, probably due to the detachable tyre plug storage case. Not a big deal if you just throw them in your pocket but if you store them with inner tubes the tool bits may catch on them and damage them

Bottom line


Its big, its heavy, its great! Especially worth the purchase if riding tubeless but enough functions to suit the majority of cyclists.

See the Crankbrothers M20 on Amazon

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