I recently set up my Wahoo Kickr trainer to use with a bike equipped with a SRAM Red drivetrain, specifically for structured threshold workouts in Erg mode. Previously, I had a Shimano cassette installed on the trainer for use with bikes running Shimano GRX drivetrains. Rather than swapping to a SRAM Red cassette'which is costly and incompatible with my Shimano-equipped bikes'I opted to try the Zwift Cog for greater flexibility.
The Zwift Cog proved to be a smart choice. It was easy to install, significantly more affordable than a new cassette, and offers micro-adjustability by rotating the cog to fine-tune chain alignment. For basic workouts, it performs reliably and meets expectations.
That said, there are a few caveats. The cog's tooth profile isn't optimized for SRAM flat-top chains, which could potentially accelerate chain wear. However, I maintain my chains regularly and am comfortable replacing them as needed. Noise levels are acceptable'not silent, but not disruptive either. One limitation is that I can't use the Zwift Click with my trainer, so I may end up selling it.
Overall, the Zwift Cog is a great solution for anyone looking to use multiple bikes on a single indoor trainer with minimal hassle. While it's not a perfect long-term solution'especially for SRAM flat-top chains'it's a versatile and cost-effective option for most training setups.
