Casette wobbling

Hello Zwift community,

I have a problem and unfortunately I have no more ideas to solve it.

On my Zwift hub, the cassette CS-HG700 incl. spacer wobbles slightly, most strongly on the outermost sprocket - shifting not ideal in some gears. I have already tried the following things (beside disassemble and reassemble several times):

  • replacement Zwift Hub (almost worse)
  • replacement freehub (no difference)
  • 2 different cassettes (no difference)

When I watch the Zwift Hub while pedaling, I see that the disc also wobbles slightly. Do any of you have similar issues with the Zwift Hub? I’m currently not sure if I should try a replacement hub again after it was almost worse than mine last time. Currently I am therefore also dealing with Wahoo trainer, can I expect then similar problems?

Thanks for your help/feedback,

I’d question whether you have the right spacer or even enough spacers. Everything you describe is symptomatic of this.

On the odd occasion I’ve had to do this when thing’s haven’t been machined as well as they should have been.

Fair point, I use the spacer that came with the CS-HG700, 1.85mm. Otherwise also all spacers that were included in the package. When trying with a Sunrace a few days ago without spacers I actually have the same result.

There are thinner spacers out there too. I’d get a collection and add one by one until you don’t have the looseness.

You’ll know if you’ve gone too far as you’ll struggle to get the lock ring on.

You’ll maybe have to adjust your high and low screws to allow for the extra travel but you’ll eventually get smooth gears.

I put my old 7 speed bike on the hub, needed a 4.5mm spacer, which I had to file notches in to clear the rivets on the hub, is it lying flat ?