What cassette size

[JapanRed]

Hi all,

New to cycling here. I’ve just ordered a Wahoo Kickr Core (new) and a road bike (used) as I want to give Zwift a go. I understand that the Kickr Core doesn’t include a cassette. Can anyone advise on how I can tell what size I need?

[nammynake]

What groupset is on your bike? Assuming it’s Shimano 11 speed you just need a compatible cassette for that set up, so 105 for example.

[JapanRed]

Sorry what’s a group set? I’ve never had a road bike before and am new to all this...

There’s 2 cogs on the front and 9 on the rear if that helps? Says Shimano 105 if that’s of any use

Edited by JapanRed on Sunday 24th January 16:25

Edit: Why do I need a cassette when there’s already one on the bike?

Edited by JapanRed on Sunday 24th January 16:28

[firemunki]

Kikr Cores' don't use the rear wheel so if you're never riding outside steel the one from the bike or you'll need a Shimano/SRAM compatible 9 speed.

9-speed cassettes should be cheap as you like since they're pretty old gen by now, that and the fact you can get the lowest spec going since weight is irrelevant on a turbo.

Don't forget if you buy one check it has the spacers to run on an 11 speed freehub (pretty sure they don't come with cassettes), you'll also need a cassette lockring tool.

[JapanRed]

firemunki said:

Kikr Cores' don't use the rear wheel so if you're never riding outside steel the one from the bike or you'll need a Shimano/SRAM compatible 9 speed.

9-speed cassettes should be cheap as you like since they're pretty old gen by now, that and the fact you can get the lowest spec going since weight is irrelevant on a turbo.

Thanks so much for the help. I won’t be riding outside so I’ll just use the existing 9 speed cassette with the supplied 1.8mm spacer.

[anonymous-user]

JapanRed said:

Thanks so much for the help. I won’t be riding outside so I’ll just use the existing 9 speed cassette with the supplied 1.8mm spacer.

Cassettes are cheap as chips - I wouldn't take the existing one off the wheel, as then you really won't be riding on the road. Leave it on the wheel so you can ride on the road if you feel like it.

[firemunki]

One thing about using a new cassette, since the current one is old and worn in (most likely) you'd also need a new chain otherwise shifting will be poor.

At this moment in time with crap weather, I'd be using the old cassette and not going outside then when it's time to go outside lots getting 2 cassettes and a new chain then swapping it all as one.

[JapanRed]

Thanks all. I’ll see how I get on with the old one but then potentially look to swap/upgrade depending on how it feels when I’m on the bike.