The weather has finally got the better of me so today I went and bought a Wahoo Kickr Core from Evans. I explained that I planned to use it with my Arkose 4 which is SRAM Rival 1×11. The only cassette they had which would work at the same ratios (11-42) was an SLX one. They assured me it would work fine. I’ve tried it tonight and it works but not well, jumpy gears, grindy noises etc. Double tap seems to be an issue. Can anyone say if these are compatible and I need to look at indexing and/or chain wear v new cassette, or am I better to get a SRAM cassette?

Also, my max gear on this setup will be 42 front – 11 rear and I seemed to spin out a bit on this going downhill in Zwift – would I be better running a bigger front ring?

Dunno about the cassette but does Zwift work in resistance or ERG mode? If the latter then you shouldn’t need to change gear, the software alters the resistance according to what you are trying to do. Stick it in the middle cog and you are good to go.

If it uses resistance mode then you should be able to change the resistance range of the turbo to match your cassette and power.

First off, have you checked your chain for wear?

Minor adjustments of the limit screws may also be required as even though its 11 speed, it’s a different freehub set up and cassette. I run the exact same cassette on my trainer as my bike and its bang on.

As for resistance, I run 40/11 as my highest gear on an Elite Direto and that can wind up some serious resistance, like above, check the settings on the app in relation to % resistance on the slider bar, 0% give naff all climbing resistance/ feel bit mega free speed DH and 100% is vice versa

MTB cassette on road hub? Have you fitted a spacer behind the cassette???

I’ve SLX cassette on CX and gravel bikes, both with Rival, fine. 11-40T though, and mechanical. And 105 or Ultegra 11-28T with Rival on road bike, fine

Try running “trainer difficulty” (slope feel) at somewhere in the 25-40% ballpark. This will reduce the power generated when climbing in any given gear at the same cadence, but on the flip side, you will generate more power when decending.

By design, Zwift treats descending as 50% even when using 100% slope feel. Something to do with fairer racing between riders with smart and dumb turbo trainers. I can’t see it now, but there was a recent article about this at https://zwiftinsider.com/

Thanks all.

It doesn’t say in the wahoo manual to add the spacer for an mtb cassette but I might try that. I played around with the barrel adjuster and it improved but still not brilliant. Will also try the cassette from the wheel on the trainer.

Is the frame qr or thru axle?

It’s a QR at the back. Anyway I think I’ve found the issue…

Went to swap the cassette out for the one on the bike and discovered that the bike shop hasn’t done a very good job of putting the cassette on…

Pretty sure the two dogs shouldn’t be right next to each other!

That’s an oops!