Have had an annoying rattle on the roadie for a while now and have tracked it down to the ultegra cassette.

It’s seated on a mavic free hub.

The highest 3 gears/chainrings seem to have a bit of play in them. Not side to side but forward and back. There is probably about 3-4mm of movement.

That’s not normal is it!? I’ve tried taking it off (no sign of wear to the free hub and correct mavic spacer used) and reseating. It was quiet for about 5 miles but is back to rattling away again.

Is the cassette knackered? Is that what they do? Have recently replaced chain ( second chain on original cassette) and changes gear perfectly with no skipping under load etc. Very annoying if I have to change it for that.

MM

10 speed cassette? If so you Need an extra spacer between cassette and hub as the 10speed is slightly narrower than 9 speed

Yes 10 speed but I’m running the spacer. Has just started rattling over the last couple of weeks.

Odd then. Some Mavic hub will need 2 spacers! One that comes with the wheel and the one that ones with a cassette.

If its been fine before its more likely a problem with the free hub body or hub itself than the cassette.

Does the free hub body have play when the cassette is removed?

No, no play.

It’s only the highest 3 gears which are on a carrier that move/have play in them

I guess the lockring is on nice and tight? I once had play in a XTR cassette aluminium carrier due to it wearing gradually over a long time but we’re talking several chain changes here.

Can only imagine that the rivets (or whatever) on the carrier have loosened (can’t believe you’ve dug several mm into the freehub

I’d take the cassette apart & have a look

I will try the cassette on the Sunday best carbon rims and see if it does the same on them. They are mavic too so should highlight the problem.

Just wondered if this was a common thing.

As I said the movement is not side to side like a spacer is missing. It’s front to back.

hang on – highest, as in smallest sprockets ?
are you sure they’re on a carrier ?

(it’s not the chain skipping by any chance – new powerlink not fitting right or maybe cassette very worn ? but I doubt it)

Sorry meant lowest (3 biggest rings on sprocket).

Chain is not skipping. Runs perfectly but rattles like mad on any rough surface…which is most of London

play in the cassette rivets, first 3 are pinned together on shimano

you on the big ring at the front ?