I am upgrading my mtb, an '04 Specialized Epic. Currently, it has a Shimano 9sp cassette on Mavic xm317 wheels, and I am looking to change to a 10 or 11 speed cassette. I am aware that I need to change shifters, derailleurs etc to get this to work, they are not part of the question.

My question is: With all Shimano components, is the limiting factor in compatibility the hub? Are there other aspects/parts which limit compatibility with newer cassettes?

2 Answers 2


Mountain hubs are the same for 8, 9, 10 and 11 speeds. 11 speed cassette is wider, but instead of making the freehub body wider, the largest cog hangs slightly over the freehub body. This means that it is possible but not likely that there is clearance for derailleur with 9 or 10 speeds but not 11.


You're on a slippery-slope of knock-on upgrades and replacements, and the main limiting factor is your budget.

Yes - your current rear wheel has either a 9 speed hub, or maybe a 10 or 11 speed hub with spacer rings. Take the cassette off and look for one or more metal spacer rings about 50mm across and anything up to 5 mm combined thickness.

There's a chance the freehub body can be swapped to a wider one, but this assumes spares for your hub are available at reasonable prices. Its not unusual to see a replacement freehub body cost as much as the whole hub WITH a freehub.

To update to 10 or 11 you also need at least

  • new shifter (hope its not combined with your brake lever)
  • new cassette
  • new chain (because you don't fit an old chain on a new cassette, and the new chain will be thinner)

You probably also want

  • new gear inner and outer, because its coming off anyway so not a lot more work to fit new ones.

At worst case you might need

  • replacement rear derailleur (but this would be pretty unlucky if your current one doesn't have enough range once the limit screws are tweaked)

Remember there's absolutely nothing wrong with 9 speed rear. The chain is a little thicker and therefore more long-lasting than 10 or 11 speed.

If you got parts for free from a dead donor bike, it would be worth doing, but otherwise it gets quite expensive for minimal gain.

  • 1
    Shimano 9, 10 & 11 speed mountain cassettes are all the same width and cable pulls for 9, 10 & 11 are incompatible. So, no new free hub, but defiantly a new derailleur unless friction shifting is an option.
    – alex
    Jun 24, 2017 at 9:28

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