Is it 11 into the same space as 10 or is it the same spacing as 10 and a wider cassette?

The top (42) is cranked in towards the spokes a little, it can be done as the spokes are further away from the chain at this point than they would be with a 36t. It requires a special ‘driver’ though in place of a normal barrel or free hub body.

There’s no dish on my XX1 42T cog, it sits perfectly flat on my table. The extra “space” is from the lack of a lock ring and a narrower chain.

Same spacing as 10 and a wider cassette. 10 speed chains work fine on XX1, it does not use a narrower chain as suggested above

sketch1981 – Member
There’s no dish on my XX1 42T cog, it sits perfectly flat on my table. The extra “space” is from the lack of a lock ring and a narrower chain.

he means the cassette is domed, because it is. look at the largest cog, the 42t one, take your cassette of and have a look… of course it would still sit flat on your desk, the doming goes towards the centre of the cassette from the outer edge

can kinda see it here: [video]https://www.youtube.com/watch?v=uZzrzhlriB4[/video]