[whatsa6speed?]

I'll apologize in advance as this may seem like a simple question . . .

Anyway, should axle nuts be "bottomed out" on the axle threads and the rear wheel then spaced? For reference, I've got a FRC roller with the standard 3/4" axle. When I bottom out the axle bolt on the thread (with the positioning spacer against the frame), the axle legs cinch together a bit. Am I doing something wrong or should I machine the spacer down a bit? Something else?

 

[whatsa6speed?]

i'm not really following your description but what you are after is to not put any side load on the wheel bearings. if the wheel uses tapered roller bearings like later harleys then you want about .003 side play. if the hub has straight rollers like early hd hubs then .001 to zero sideplay. also fork tubes should not "pinch together" when the axle is tightened. it would help if i knew what wheel and frontend you have.

oops, just reread your post. you're working on the back wheel. same advice though on the bearings. on the rear when dealing with spacers the first objective is proper chain or belt alignment then centering the tire in the frame. it can range from easy to nightmare .

Thanks so much for getting back to me.

It looks like I'm on the right path.