Are the shoulders that you get on axles with sealed bearings there so the right amount of axle sticking out on the gear side – rather then being necessary for the correct operation of the bearing as such?

I ask because I have an older sealed hub that I’m thinking of using with a 6 speed freewheel on a 130mm frame, so if I re-space it, the wheel would have very little or no dish. But this would mean removing the shouldered axle it came with and replacing it am ordinary ‘shoulderless’ one. As far as I can see, as long as the inner race of the bearing is a good fit over the axle this should work.

I know well-built dished wheels are just fine, this is for interest….

The shoulder on the axle will be exactly the same width as the housing for the outer race on the hub shell, it stops the inner race from running out of line with the outer race, as would happen when you tighten the qr if the hub has slide-on axle spacers. If you have a threaded axle with lock-nuts, it could be possible to do it as long as you’re careful not to pre-load the bearings (think HT2 bottom brackets, and how quickly they die if over tightened).