So, you’ve got yourself a shiny new turbo trainer, like the Tacx Flux S, and jumped the gun a bit on buying a cassette for it. Maybe you, like many of us, relied on a quick Google search to determine your bike’s speed, only to find out after the fact that you’ve got a 10-speed bike, but now a brand new 11-speed cassette proudly sits on your trainer. You’re not alone! After a slightly clunky first session, the question arises: Is this 10 vs 11 speed cassette mismatch a major cycling faux pas, or can you ride it out?
As a novice cyclist, encountering gear issues can feel daunting. The immediate concern is whether this setup is rideable and if those gear changes that sound and feel less than smooth are going to cause damage or ruin your indoor cycling experience. The good news is, in the short term, you can likely still ride your 10-speed bike on a turbo trainer equipped with an 11-speed cassette.
However, it’s not ideal. The primary issue stems from spacing. An 11-speed cassette is narrower than a 10-speed cassette. This means your 10-speed bike’s rear derailleur and shifters are designed to move the chain across a wider range. When using an 11-speed cassette, the spacing between sprockets is smaller, and your 10-speed system will likely be trying to shift to positions that don’t quite align with the 11-speed cassette’s sprockets. This is what causes the clunky shifting you’re experiencing.
You might be tempted to adjust your derailleur indexing to compensate for the 11-speed cassette while on the trainer. While you could potentially tweak the barrel adjuster to improve shifting on the trainer, this is generally not recommended as a long-term solution. Constantly readjusting your derailleur every time you switch between your trainer and the road is inconvenient and can lead to inconsistent shifting performance in both scenarios. Furthermore, forcing a 10-speed derailleur to work perfectly with an 11-speed cassette is unlikely to be entirely successful, and you may still experience less-than-perfect shifting.
Think of it this way: you can probably wear shoes that are half a size too big or too small and still walk, but it’s not going to be comfortable or efficient, and over time, it might cause problems. Similarly, while your 10-speed bike might function on an 11-speed cassette for turbo training, it’s not the optimal setup for smooth, reliable performance.
For now, especially if you’re focusing on mountain biking during the winter months, you can likely continue using your current setup for indoor training. Just be aware that the shifting might not be as crisp as it should be. However, for the best long-term solution and to avoid potential wear and tear on your components, especially if you plan to use the turbo trainer frequently, the most recommended approach is to install the correct 10-speed cassette on your turbo trainer.
While the sunk cost of the 11-speed cassette is unfortunate, consider it a learning experience. For future bike component purchases, always double-check your bike’s specifications before ordering! In the meantime, you can decide whether to live with slightly compromised shifting on your trainer or invest in the correct 10-speed cassette for a smoother, more compatible indoor cycling experience.
