Road bikes are built to face different challenges than MTBs. Does this lead to difference in the crank strenght versus weight optimization? Will road cranks tackle to the occasional bump onto a stone on the trail?

  • Aside from exotic units I doubt that there's any significant difference. The main differences would be in shaft length, shaft offset, body length, etc. Oct 4, 2013 at 11:12
  • There might be issues with compatibility. If you look at things like Hollowtech, road cranks are usually made for 68mm, while mountain bike are often 73 mm. This doesn't matter for square taper and octolink, because this is all handled by the bottom bracket, but with hollowtech, the drive has part of the axle built into the drive side crank, so road cranks may not work with your mountain bike. Also, there might be issues if you are using road chainrings as well, as they are larger and might interfere with the chainstays, which is usually splayed out further to accommodate larger tires.
    – Kibbee
    Oct 4, 2013 at 13:15

1 Answer 1


In general, road cranks are lighter because they use less material than mtb cranks. Mtb cranks use more material so they can handle more abuse. Compatibility aside, I would be cautious in using road cranks for much more than cyclocross duty. You may never have a problem, but do you really want to find out the hard way?

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