Is that possible? I discovered my blur bearings had disintegrated over the last few rides and the back end is flexing badly side to side. The chain is slipping under power on bottom two cogs of an apparently unworn cassette and chain.
I am obviously replacing the bearings but wonder if the slipping could be cased by this?

Not sure. On my Nomad I had an occasional skip on my month and bit old cassette and chain (though it’s just done Morzine) and I’m getting loads of sideways wobble/play. Usual lower link tighten and greasing hasn’t solved it. Dropped it off to be looked at thinking it’s bearings but initial inspection suggests the hub. Which might explain affect on the cassette.

Update: verdict is frame bearings after all as I originally thought. That’s being sorted so will report back on chain slip if any. Like you I was only getting it under power on certain cogs. Suggests worn. Worked out that despite a short space of time I’ve done 150ish miles on the cassette and chain. Shouldn’t be that worn though.

Frame bearings done. Frame play gone at least and no noticeable chain slip. Though it did need a bit of gear adjustment. suggests some affect on alignment perhaps.

Anyway, turns out hub bearings also needed doing. Just done them, and BB. Hopefully that’s everything serviced (really is just about everything)… until the next mud ride and looks like that may tomorrow 😀

Similarly with my Nicolai. Since returning from three weeks of riding in Scotland I’ve had to replace the main pivot bearings when I noticed the chain catching on the rear tyre as the swingman was pulled out of line when pedalling. All good now- I hope.