Shimming Eccentric Bottom Brackets

Recently, I put together a 17" 2006 Zion 660EBB Singlespeed frame.

It has an eccentric bottom bracket with dual locking set screws. One huge problem with this system is that the eccentric doesn't even come close to fitting the shell snug. It has room to rock around like they were two unsuited parts. This will lead to problems in the future if not soon.

The shell measures 2.141" to 2.150" (slightly distorted due to welding) The eccentric measures 2.126"

By having a well greased snug fit, the bottom bracket will have much less room to rock around and creek. Also, it will require much less clamping force with the screws to keep it in place. This is nice for long term service, as well as keeping the eccentric from spinning when hitting rocks.

I will fill the gap using some stainess steel shim stock. At this point, I have to cut some 0.0075" and some 0.010" stock to find out what works best.