Mechanical issue with my Tacx Flux 2 Smart

Hi everybody,

Whenever I stop pedalling on my trainer, the chain gets loose, then the derailleur tightens until it makes a big clanking noise, and then the chain gets loose again, then the derailleur tightens etc…

So, when I want to stop, I either have to keep pedalling slower and slower, or unclip my pedals and let them turn by themselves until they stop.

I am using the same cassette as on my bike (Sram 9 speed, 11-26), which I have set up according to the user’s guide.

What could be the problem here?

Thanks in advance.

Additional note: when my trainer is off and I try to backpedal, the same process of the chain getting loose and the derailleur tightening happens 2 or 3 times before I can actually backpedal.

That doesn’t sound right at all. How old is the chain? Did it used to be fine on the trainer or have you recently moved on to the trainer?

The chain might have got a bit stiff and hence do strange things where it locks into shape in places. If so, some lubrication may well help, or it might be time for a new chain.