Hi All, Before the parts arrive, can anyone clarify for me whether I will need a spacer behind the cassette to fit a 10sp Ultegra cassette to a Hope RS 4 free hub please?
If so, is the spacer likely to arrive with the cassette?

1. not sure
2. yes

Yeah spacer needed

You’ll need 2 spacers. A 1mm spacer that comes with the cassette and an 11spd spacer that will come with the wheel.

Thanks guys. Do they both go behind the cassette?

Yes.

You need the spacer Hope should have supplied because the hub is 11speed road compatible and needs a spacer for anything that isn’t 11speed Road (including 11sp mtb which is standard 10sp length). You need the spacer Shimano should supply because it’s needed to properly fit s 10sp Road cassette. Both go behind the cassette.