It's been bugging me how far out these Lesu wheels sit. Here you can see part of the problem. The recess in the wheel for the hex is a solid 6mm deep. So best case, you're running a pretty wide 6mm hex just to keep the wheels off the axle. Pictured is a 5mm hex with a 1.5mm washer acting as a spacer. In this configuration, just more than half of the tire stuck outside the fenders!
So I decided to take matters into my own hands.
I wanted to shoot for the ability to run a narrow 4mm hex to bring the track width inward 2mm per side. I stacked 4mm of washers into the wheel and took out the Dremel and my metal cut off wheel.
Using a steady hand I kept the blade flush to the washers as best I could and proceeded to cut down the recess in the wheel.
After the initial cut, things were functional, but kinda ugly.
I took a flapper wheel to it and it looked much better afterward.
It's hard to capture on "film", but now more than half of the tires are covered by the fenders with a 5mm hex. I have some 4mm hexes on order so we'll see if I can narrow it down just a bit more.