No clicks from freehub "nut", OK?
 

So I have another noobie question. In order to try out SS I bought a cheap Nashbar spacer/tensioner kit. I've noticed that the "nut" that holds the spacers and cog on the freehub is not notched like most ones that come with a cassette are. Obviously it doesn't click when you tighten it. Any chance it could work loose?

I have an old cassette all broken down and am considering using the smallest cog from it in place of the last spacer. It fits on the half splines nicely and the matching "nut" confidently clicks into place. However I really don't want to do this unless loosening could be a problem.

edit: "nut" = lockring, Duh

it'll probably be fine. because of the freehub, there aren't any strong counterclockwise forces on the hub. if you are particularly concerned about it, you might throw some blue loctite on there.

the clicks are ridges on the lockring skating over the splines on the cog. since those freewheel spacers have no ridges, you get no clicks.

makes sense that it'd be disconcerting, but it's not a problem. since there's no direct torsional force on the lockring it's very unlikely to come unscrewed. just crank it on there, check it once a year maybe, you'll be fine.

nothing wrong with your other solution either, do that if it makes you feel better.