8 Speed Cassette Wahoo Kickr Core

Hey all,

Just getting into the whole trainer / Zwift experience, and just want to make sure I’m not doing something wrong, or if there is a better way to install the cassette

I have fit my 8 speed cassette to the Core, using the provided spacer. I then put my bike on it, and the experience wasn’t great to be fair (It’s a cheap road bike from Halfords). I’ve managed to get it so it’s acceptable to work on the mid gears, but at the lower and higher cogs on the rear derailleur it’s not very smooth at all.

I’m gonna get the bike serviced, as it was never really used outside, and have just found that the gear changing was pretty terrible on the road anyway (doesn’t even get to the larger cog on the front derailleur. But I’m also just wondering if it’s worth getting an additional spacer, as Wahoo’s instructions is basically “use the correct spacers”. Thanks - which ones are they?

The cassette I’m using is the Shimano HG50 11-28. Any advice would be very welcome, and whether I need to purchase an additional spacer in addition to a service.


You could take the trainer with the bike to the bike shop so they can check the spacing and indexing on the trainer as well.

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i brought my bike and kickr trainer in for a cleaning/tuning. basically, the trainer has become my back wheel!

the only bummer on this is that it’s super heavy to carry a kickr.

You need one 1.85mm spacer (proper Shimano one is best, the part number is FH-9000 or Y4T724000), situated behind the cassette. Should work fine, with little tweaking necessary if shifting is already good on the actual wheel.

If you’ve been having problems with the gears on the bike on the road, changing the rear wheel to a trainer certainly isn’t going fix anything… Figuring out if the existing spacer is or isn’t enough is pretty simple, just see if you can move any of the cogs sideways even a little bit by hand, and if not, you should be fine on that front. One extra thing you could check is that the cogs are spaced evenly, some cassettes have spacers with different widths for different positions and they can get switched around easily if you aren’t paying attention.

But overall this sounds to me just like your gears need a bit of adjusting, and if that isn’t enough, you may have to replace something or explore more complicated repairs (checking if the derailleur hanger is bent and what else).


I have previously run the Kickr Core with an 8-speed Shimano cassette, no problems. But you need a spacer. The Kickr Core is provided with a spacer, which is not enough for an 8-speed cassette. I found an additional spacer intended for running an 8-speed cassette on a 10-speed wheel, and that worked perfectly fine with the Kickr Core.

So it is possible, just make sure you have the correct spacer(s)

Hey all,

Thanks for the advice. I changed the spacer, and had a new chain fitted which has made a world of difference…Now just to fix the resistance issues I’ve been having!!