In a question earlier today (Changing cassette from 8 to 10 or 11 to meet the Shimano 105 5800 groupset) the Op asserts that they would need to change their hub, if they wanted to go from a 10- to 11- speed cassette.

I'm not very clued up on 11-speed systems, was wondering why this is the case? And, presumably, when they say "hub", they mean just the freehub body?

example of freehub budy

Or do they mean something else/more?

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    @Blam I thought 8/9/10 are exactly same.
    – Alexander
    Commented Feb 8, 2015 at 21:23

4 Answers 4


Shimano/SRAM 11 speed cassettes are wider than 8/9/10 speed ones. So yes, you need a new, wider freehub body, unless your old one was not very old and used a spacer to fit a 10-speed cassette.

People with non-Shimano brand hubs are less likely to find replacement freehub bodies, it seems, leading to replacement of the whole hub, or even the whole wheel if the old rim isn't worth relacing.

For more on this, read the last question and answer here: http://velonews.competitor.com/2013/09/bikes-and-tech/technical-faq/technical-faq-drivetrain-compatibility-for-10-and-11-speed_301392

There's also a compatibility chart here: http://www.slowtwitch.com/Tech/Cassette_Spacers_2013_3978.html

Campagnolo cassettes are the same width for 9, 10, and 11 speeds, so you don't need to do anything in most cases.

  • Thanks John, your answer and the links explain things nicely. Actually I have a couple of excellent books on bike maintenance, written by none other than Lennard Zinn, I must have a closer look at Velonews
    – PeteH
    Commented Feb 9, 2015 at 11:43

As you're not clear on road vs mtb, there's two answers.

For 11 spd road drivetrains Shimano uses a 1.85mm wider hub with the drive side flange closer to the centerline to compensate for the additional width. Using a spacer allows the wheel to be backwards compatible to fit a 10 spd cassette. You can't fit a 11spd freehub in place of a 10spd freehub unless the wheel has been built to accommodate it.

Some hubs are, usually 2012 or later hubs from better brands, are able to be converted. Others are not. It is different for each brand.

For 1x11 MTB drive trains SRAM has designed the XD driver which fits a 11 speed cassette but is a different shape and not backwards compatible with 8/9/10 speed cassettes.

  • Thanks for this, I was asking purely for my own education, so both road and mtb are of interest.
    – PeteH
    Commented Feb 9, 2015 at 11:57
  • Does it mean, that 10/11 speed MTB shimano are same? You mentioned only road.
    – Alexander
    Commented Feb 9, 2015 at 20:12
  • Forgot about the xtr 11 spd. Haven't seen one yet but think it uses a 10 spd hub.
    – DWGKNZ
    Commented Feb 10, 2015 at 5:03
  • @Alexander, Shimano 11 speed mountain are 10 speed compatible, the larger cogs can clear the spokes without extra width on the freehub.
    – alex
    Commented Jun 3, 2016 at 8:07
  • I'm fitting an 11spd cassette on a Shimano HG freehub (mtn bike) and while the cassette fits properly the top cap rubs against the drop outs once tightened, so you may (as in my case) need to add a spacer
    – markd
    Commented Dec 9, 2017 at 15:46

I work in a bike shop. We found a simple way to modify 11 speed cassettes (105' Ultegra, Force, Rival) to fit 9-10 speed hubs. Precise machining is done on a lathe with a special jig. A tiny amount of material is carefully removed from the back of the cassette so that it will fit the 10 speed hub perfectly.
All 11 speed are usable and shifting is as is should be...Flawless!!!

  • 1
    Wow, a blatant commercial promotion ... that is actually a useful answer to the question :)
    – Móż
    Commented Oct 12, 2016 at 2:32
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    Welcome to Bicycles @Hugo. We recommend new members take the tour to make best use of the site, and since you're answering How to Answer is worthwhile also. See also the last para of this help center page. Since your answer is a) useful and b) mostly about your product, I suggest that you edit it to make sure it addresses the main point of the question.
    – andy256
    Commented Oct 12, 2016 at 3:38

You can machine a road cassette in your own bike shop without a lathe. You need a head tube reamer/facer with just the facer tool attached. enter image description here enter image description here enter image description here enter image description here enter image description here

  • 2
    This is a good answer to a slightly different question. The question is "(are there) special hub requirements for an 11 speed group" and this answers "how to mod an 11 speed cassette to fit an older hub" You could ask-and-answer this as a new question, and answering your own question is totally allowed, even encouraged. Do have a browse of the tour too please.
    – Criggie
    Commented Apr 13, 2019 at 21:55

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