changing back wheel for turbo trainer - same size cassette needed?

Slinkie · 19 Oct 2016 at 09:49

Hi all,

I had an entry level road bike with 7 gears on the back. I had spare back wheel with a trainer tyre on for when I used the turbo trainer that I could switch between. I now have a new bike with 11 gears at the back. To use an 11 gear cassette I'll need to get a new wheel and cassette as my current spare isn't right for a larger cassette. Can I just use my 7 gear cassette with my new bike , making sure I don't change gear while I am on the bike (to prevent missing gears, dropping the chain etc) I can just change the resistance by using the front gears and the resistance modifier on the trainer itself.

Jono · 19 Oct 2016 at 09:51

Worth a shot. Problem may be if the indexing of the 11 gears doesn't match any of the sprockets on the 7 ring cassette.
I'm not even sure if the 11s chain would be wide enough ?

touch · 19 Oct 2016 at 09:58

No, the 11 speed chain will be narrower.

You might be able to bodge it by replacing the 7 speed cassette with a load of spacers and a single sprocket from an 11 speed cassette if you only want the 1 gear.

Jono · 19 Oct 2016 at 10:08

I'd just buy an el-cheapo back wheel, for about £20 from someone who upgraded their bog standard wheels with something like a pair of zondas.
I don't know if the .... bit you slot the cassette on has changed over the years? I suspect it has, I think my one supports 9/10/11s... but not 7/8.

Then buy a cheapo tiagra 11s cassette to suit your chain length/derailleur size.

Jono · 19 Oct 2016 at 10:10

I wouldn't want to be limited to only one gear at the back. It'd suck, and be terrible for training, surely negating the point of having a trainer.

Slinkie · 19 Oct 2016 at 11:40

I think I'm just going to change the tyre then everytime I want to go on the trainer. Will this cause any issues with my road tyre? Ie constantly taking it off and changing it back? I assume as the weather gets worse and worse I will be on the trainer more than outside.

lordrobs · 19 Oct 2016 at 23:20

I predict that will end up with either a trainer that is never used or a bike that never sees the road

I think a cheap spare wheel is the best bet.