I bought a used Tacx Flux Smart. I need to replace the fitted cassette and install my own Shimano 9 speed cassette. According to the instructions, I need a spacer ring for this. This was not included with the purchase. I have now found some spacer rings, but I don’t know which one is the right one. Can you help me?
Small correction - for a 9-speed cassette you need a 0.85mm spacer to fit it on a 11-speed Shimano freehub. The 1.85mm spacer is only needed to fit a 10-speed cassette onto a 11-speed freehub.