If you're looking to adapt your Tacx direct drive trainer to work with either a Campagnolo or Shimano/SRAM cassette, or perhaps just need a replacement freehub, this 11-speed freehub body is what you need. Pairing Campy cassettes with Campy drivetrains, and likewise Shimano with Shimano and SRAM with SRAM ensures the best shifting performance. This is why we recommend keeping the cassette on your trainer consistent with the one that's already on your bike for the best overall experience. This freehub body works with both the Neo and Flux trainers from Tacx, and features a durable aluminum construction with a steel insert that helps prevent the cassette from notching up the freehub body.