Cassette replacement - removal and installation

This article describes removing and installing a cassette (8, 9, 10, 11, or 12 speed) on a CORE's stock Shimano/SRAM HG 11 speed freehub.  Campagnolo and SRAM XD/XDR cassettes require a different freehub (sold separately). For purchase and installation instructions for those drivetrains, see
Campagnolo: freehub purchase | freehub installation instructions
SRAM XD/XDR: freehub purchase | freehub installation instructions
For more information on drivetrain compatibility for KICKR wheel-off smart trainers (including KICKR, MOVE, and CORE, see Drivetrain Compatibility for KICKR MOVE, KICKR, and CORE.

Required Tools:


  1. Remove the quick release and drive side QR adapter or thru axle spin cap, if present.

  2. Secure the chain whip, cassette vise, or pliers around a cog in the middle of the cassette with the handle(s) toward the front of the cassette. If using a chain whip, drape the chain over the top of the cassette from back to front. This will allow you to apply downward force on the tool to prevent the cassette spinning backward when loosening the lock ring.

  3. Insert the cassette lock ring tool into the cassette lock ring fully, and secure the wrench to the lock ring tool.

  4. Push or pull the cassette lockring tool counter-clockwise while using the chain whip or cassette vise/pliers to brace cassette in place. You will hear a ratcheting/notching noise as the lock ring breaks free.

  5. Once loose, you can remove the wrench and use the lock ring tool or your fingers to unthread the lock ring by hand.

  6. When the lock ring is gone, gently pull the cassette outward with both hands, noting that the cogs will be loose when free of the freehub body. Having a zip tie handy to loop through a cassette to ensure the order of the cogs is maintained can be helpful.



  1. 11 speed cassettes and 12 speed road cassettes do not require a spacer. 

    7-10 speed cassettes require additional spacers. 
    • 8, 9, and 10 speed cassettes will require a 1.8mm spacer (included with new trainers).
    • 7 speed cassettes will require the 1.8mm spacer AND a 4.5mm spacer (to be purchased separately from your preferred local or online retailer). 

  2. If your new cassette includes an additional spacer (ex. 1mm spacers with Shimano 10 speed road cassettes), install this before installing the cassette. Otherwise, install the new cassette. directly.

  3. Examine the freehub body and note the location of the one spline that is narrower than the others. This keyed pattern exists on the inside edge of the cassette cogs and ensures that the cassette can only be installed one way. Rotate the narrow spline to the top and then install cogs and spacers as a group or one by one, ensuring that the cogs are installed large to small. 
    core-freehubsplines-arrows.png cassetteinstall-keyedsplines-400.png
  4. If you drop any cogs or spacers, know that
    • Cogs can only be installed one way.
    • Some of the rearmost cogs may be pinned together or mounted on a carrier as a group.
    • All spacers are identical, interchangeable, and reversible.
    • Generally, there should be a spacer between each cog, except for the last few, where each has a built-in spacer. You will see that they have a thicker profile.

  5. Ensure that the last cog is installed in the correct orientation relative to the key spline, and remains there as you install the lock ring.  It can sometimes be difficult to keep it in place during installation.  This cog moving during lock ring installation is often the cause of drivetrain noise or cassette instability as it is compressed into the freehub without properly compressing the cogs behind it.

  6. Thread the cassette lock ring by hand.  Be careful not to crossthread the lock ring. One good way is to rotate the lock ring counter-clockwise until you feel a notching sensation as the first threads fall past one another. Then start rotating clockwise.

  7. Use cassette tool to snug the lockring, bracing the large pulley wheel with your hand.  Once snug, tighten further another 6 - 10 clicks (roughly 1/4 turn).

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