Originally Posted by
Brusilov
Well, I'm not sure how to disassemble the front free-wheel; the crank came apart easily enough, but I want to take the FFS apart as well to clean and re-grease the bearings.
I'm also still not sure; provided I wanted to convert it to single speed, would I have to buy some special rear cog or would any aftermarket thing on amazon work? After hearing that the rear cogs need a special tool that isn't the typical Shimano to take them off, I'm concerned about their compatibility with standard bike technology.
Well, you could convert it to single speed by eliminating the derailleur and shortening the chain. I would run it on the small chainring and the second-smallest cog, with 17 teeth. That's kind of low geared, and the chain angle is extreme, but it'll work.
Note that this won't be a "fixed" gear. You'll still be able to coast, and you should keep both caliper brakes in good working order.
Converting it to a more-conventional non-freewheeling chainwheel and single cog (fixed or freewheeling) is possible, but much more involved.