Hi everyone!
I’d like to buy a Tacx Flux S trainer but I can’t understand if I can use my old racing bike on it.
Instructions say that Flux S is compatible with every Shimano cassette from 8 to 11 speed, but my bike has an old 7 speed Shimano cassette. Does it fit anyway or it will be to small and there will be problems?!
Thanks for your help and sorry for my English.
Just bought one and the plan was to use my old MTB that has a 8-speed Shimano system. The cassette fitted with the spacer that that was included, but when I tried to fit the bike it did not attach… It seems that older MTB’s (like mine) has a 145mm rear hub while the standard now-days is 135mm. No adapters included for that 145mm setting (but there is adapters for some trough-axels included).
Tomorrow I´m forced to fit my full-suspension MTB in my Flux S… A bit overkill perhaps 
Thanks for your answer.
Sorry but my English is not so good so I didn’t get the problem you had. I understood that the space in your MB where the wheel should be is too wide for the Tacx Flux S, is it right? So I should measure that space on my old bike and check if it’s 135mm. Did I get it right?!
Thanks again for your help and sorry for my bad English.
English is not my native tounge either, no problem!
The manual says “Width of rear fork: Race 130 mm, MTB 135 mm. Adapters for other widths available”. So you have to measure the width of your bikes rear wheel or investigate if there is an adapter to buy from Tacx.
In this page https://www.bikeman.com/bicycle-repair-tech-info/bikeman-tech-info/1640-how-many-gears-can-i-put-on-this-thingI found the following text: " Simply put - 8, 9, 10 speed cassettes all fit on the same hub . A seven speed cassette will fit on an 8 speed freehub with the use of a spacer. (One notable exception is the Dura Ace FH-7801 hub with an alloy freehub which will only accept 10 speed Shimano cassettes - the newer Dura Ace hubs can run 8/9/10).".