Picked up the Kickr 2nd hand without thinking about the cassette etc. details. Not too fussed about having all 11 ratios on the trainer so wondering if installing a spacer or similar will work or do I need (and can I) to fit an 11 spd cassette to the wahoo?

2 Answers 2


Presumably the Kickr has a '10 speed' 34.95mm freehub body rather than a '11 speed' 36.75mm one.

Some wider-range 11 speed cassettes come with a 1.8mm spacer and will in fact fit on a 10 speed freehub body. The larger sprockets allows the spider to overhang the inboard end of the freehub body without the sprockets interfering with the spokes (which you of course don't have on the trainer).

  • Thanks! Wahoo website says they come with "an 11-speed compatible Shimano freehub body" which I assume means I can switch out the cassette for a Shimano 11 speed, just wondering if there's any option to retain the 10 spd cassette but help its alignment to the 11 spd Ultegra
    – MartinP
    Aug 17, 2019 at 12:53
  • 1
    With a 1.8mm spacer on the 10 speed cassette I imagine the 11 tooth sprocket sits in approximately the same place as with an 11 speed cassette. 10 speed sprockets are slightly wider spaced than 11 speed, so your indexing will get worse as you move to the larger sprockets. I personally would not do this as it would be possible to shift beyond the 10th sprocket with possible nasty results. Aug 17, 2019 at 13:04
  • Ok, many thanks, will get an 11 spd and save the heartache...
    – MartinP
    Aug 17, 2019 at 13:15
  • @MartinP. You'll need the usual tools, chain-whip and cassette tool, of course.
    – Carel
    Aug 17, 2019 at 14:45

Because the Kickr will adjust resistance on the fly for you (in ERG mode), I've found it possible to run the wrong derailleur with the factory 11 speed cassette. Just find a gear where it is lined up pretty well and don't shift. Shifting won't matter anyway, because if you shift to a lower gear to spin, the Kickr will just increase the resistance. You can also adjust resistance manually from the companion app or an Elemnt bike computer to control power/cadence.


As mentioned by Andy in the comments, you may have issues working with apps that automatically control resistance such as Zwift or RGT Cycling.

Not sure what you are getting at with a spacer for the conversion...the indexing would be way off because an 11 speed cassette has the cogs closer to each other than a 10 speed (that's why you can use an 11 speed chain on a 10, but not vice versa).

As far as installing an 11 speed cassette, that should be fine (it's actually stock). You can even get it straight from Wahoo if you like: https://www.wahoofitness.com/devices/accessories/11-speed-cassette.

  • It should be noted that using 1 gear and letting ERG handle resistance isn't going to work for Zwift etc
    – Andy P
    Sep 17, 2019 at 7:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.