Originally Posted by sciencemonster

In my quest to customize my bike absolutely as much as I possibly can, I customized one of those great quality, but cheap $12 SIS compatible 7 speed freewheels. Thought someone might be interested that it can be done.

I wanted 'corncob' gearing so I can tool around and impress people, but I needed a bailout gear for those steep driveways you occasionally encounter.

I took a 13-15-17-19-21-24-28 and a 14-16-18-21-24-28 and managed to combine them into a 13-14-15-16-17-19-28. Works like a charm! Of course, I had to get a few extra cogs off loosescrews, and had to spend a little time with the dremel...

I couldn't find anything off the shelf, and the stuff out there that was closely spaced was without the ramps that make the Shimano freewheels work so well. I've got the thing shifting perfectly with 8-speed ergos.

As you can see, I still have to take a sharpie to that big cog...