Spacers? pic included
 

I have a set of wheels that does not want to fit my old Sekine bike frame and I was wondering if these black lugnut looking things can be removed. I haven't tried to take them off yet as I thought I would ask before reefing on them.http://img146.imageshack.us/img146/5697/dsc00337yk6.jpg

They could possibly be replaced by thinner ones.
You don't want to remove them, they act as locknuts against the nut just inside of it.

Ok good to know thanks.

Consult Sheldon Brown's website on how to spread the rear triangle of steel frames. It's really quite easy with a 4 x 2 plank and a chair. That way you won' t have to interfere with the integrity of the hub, and it will be a permanent fix.

Like randomgear indicated, if you remove those over locknuts, you run into problems with loose bearings or worse, scored axle and/or broken races.

Is that a front or a rear?