Modify geared hub to fit a 110mm frame I have a kids' 18" bike with a fixed gear and a coaster-brake. I would like to replace the rear hub with a (preferably 3-)geared hub with a coaster brake as it is the kind of brake my kid is most comfortable with.

The problem I am facing is that it is an aluminium frame bike and it only would take a hub with 110mm OLD. Yet, all the hubs I am able to find are 116-120 (Sturmey Archer S2, SRAM T3, Shimano Nexus SG3C-41) or even 130mm (SRAM i-Motion) in width.

Is there any chance of modifying the Shimano Nexus or the Sturmey Archer hubs to fit a 110mm frame (e.g. by replacing the outer screw/lock nuts with narrower variants)?
I finally got it going using a Shimano Nexus 3 (SG-3C41). Looking at the pics, I figured that I could remove the massive outer distance nuts to make it fit a narrower fork:




This was not quite sufficient to get it to 110mm so I had to make use of an angle grinder to cut a couple of mm off the cone-shaped nut on the right side of the axle.

The most tedious part of it all was finding an 18" bicycle rim with 36 holes. I could not get one, so I ordered a 32-hole rim ending up with three different spoke lengths (3-crossed) in the wheel. It took me some effort to figure out of how to lace the wheel and seems to bring some durability / stability issues due to the difference in spoke tensions, but this is a kid's bike after all so great strain on the rear wheel is not to be expected.