XDR-compatible freehub bodies (aka “drivers”) for the Zwift Hub trainer are available for purchase in the Zwift Shop.
If your bike is equipped with a SRAM 12 speed drivetrain, one of the options to use it with a Zwift Hub trainer is to replace the Shimano Hyperglide (HG)-compatible driver and retrofit an XDR driver that allows you to mount a SRAM-manufactured 12 speed cassette.
- Using a SRAM-manufactured 12 speed cassette provides optimal shifting and mechanical compatibility with SRAM drivetrains.
- Selecting a cassette with the same gear range for both the rear wheel and the trainer minimizes the need to readjust your shifting.
- Note: SRAM also manufactures 12 speed cassettes compatible with Shimano HG drivers. Verify SRAM’s specifications to see which cassettes are for XD / XDR / HG drivers.
Step 1: Remove the Hyperglide-compatible gear cassette from your Hub trainer. This step gives your tools easy access to remove the axle ends in the next step.
Step 2: Follow these instructions to remove the Hyperglide freehub body, and install the XDR freehub body in its place.
Step 3. Determine if your SRAM 12 speed cassette is for use with road / gravel (XDR) or mountain bike (XD) drivers. XDR drivers are 1.85 mm longer than XD cassettes, and require a 1.85mm shim behind the largest cog to take up that extra space. More information about the difference on SRAM’s website.
Step 4: Only if needed - install one 1.85 mm spacer. Then slide the cassette onto the driver. The splines are shaped in a way that will allow the cassette to slide on in one position. Follow the instructions on the Support Hub.
Please contact Zwift Community Support for one-on-one assistance if you need. We’re here to help!