Bicycle Mechanics - How much to tighten a cassette

I have a new set of Easton Circuit wheels and have installed a Shimano Ultegra 10 speed casette, I have a rattle on rough roads. The noise sounds like it is coming from around the casette and have been unable to duplicate the rattle on the workstand.
The lockring says to tighten to 40 NM. When I tightened the lockring to that spec, the freewheel seemed to bind up a little - I loosened the lockring slightly. The individual sprockets have a small amount of play now and I suspect that is where the rattle is coming from.
Should the lockring be tightened to where the sprockets have no play? How strong is the freewheel body - Will it warp with 40 NM torque on the lockring?

A cassette has to be cranked down pretty hard. I don't think it should cause binding though, in the freewheel...

Take the wheel off and bounce it.

Should the lockring be tightened to where the sprockets have no play? How strong is the freewheel body - Will it warp with 40 NM torque on the lockring?

The lockring absolutely should be tight, so the cogs can't move around. That should not cause any deforming of the freehub body, it's very strong. If there's really some binding when you torque the lockring properly, check that your cassette is installed properly. Good idea mentioned above, to try to duplicate the rattle by bouncing the wheel!

A 10-speed cassette is actually a little bit narrower than a 9-speed cassette. You need to put a 1mm spacer behind the cassette to take up the play.

30 ft-lb (40 Nm).

If it actually is binding, you have a different problem.

A 10-speed cassette is actually a little bit narrower than a 9-speed cassette. You need to put a 1mm spacer behind the cassette to take up the play.


Thanks Retro Grouch. The inside spacer was not there - guess I lost it. Anyway, installed a new one - Problem solved. Thanks