Cassette spacer confusion (11s road)

Swapping out the cassette on K’s road bike.

11s Shimano cassettes.  Unknown hub (came fitted to the Cube bike) but the free hub is labelled 11speed.

Old was a 32t, new is 34t but they both appear to be the same ‘level’ – 3 biggest cogs on an alu carrier, the rest loose with spacers.   New one previously fitted very briefly to a wheel off trainer but ridden a handful of times.

new one is loose on the free hub when fitted.  I didn’t notice a spacer behind the old cassette (and it’s not in the bag I’ve put the old one in, nor on the floor that I can see. I don’t seem to have missed any spacers between cogs. What have I missed?

Can I just shove one of the ‘between cog’ spacers from the old cassette behind the new one?

Spacers range in thickness but try it. Make sure if you do that the final cog is on the splines

The 11/34 cassette should have come with a 1.85mm spacer that goes onto the freehub before you fit the cassette. Not sure what width the 11spd cassette spacers are but I think they are wider than this.

Aren’t 11 speed road cassettes a little wider than 11 speed MTB ones? If it’s an 11 speed road freehub with an 11 speed road cassette it should fit without a spacer. If the cassette is being replaced with an 11 speed MTB cassette it would need a spacer.

Ha. That spacer is clearly lost when I took it off the trainer. The between cog spacers are 2.2mm

wtf does the 34 have a spacer and the 32 not.

Can you get them aftermarket or do I need to buy ano ther cassette?

wtf does the 34 have a spacer and the 32 not.

Because it’s designed to work on 10spd and 11spd freehubs

Can you get them aftermarket

Yes

https://www.sjscycles.co.uk/hub-spares/shimano-duraace-fh9000-rear-right-low-spacer-185mm-y4t724000/

I had to buy a 0.5mm spacer to fit a different cassette I had for my son’s unbranded hub. It cost a couple of quid but was still annoying having to try different thicknesses and then waiting for it to be delivered.

@simondbarnes. Thanks for the tips. Dirty hands in workshop so not the moment to search. (Though doesn’t answer why the 32t cassette doesn’t have a separate spacer)

Though doesn’t answer why the 32t cassette doesn’t have a separate spacer)

Because the 32t cog is too small to be spaced over the back of a 10spd freehub.

 (Though doesn’t answer why the 32t cassette doesn’t have a separate spacer)

Easiest way to look at it is that the 32 is a large road cassette (11 speed freehub fitment) and the 34 is a small mtb cassette (10 speed freehub fitment, so needs a spacer to fit an 11 speed road freehub).