My Xootr Swift single-speed conversion project:



Parts:

1.) Fibonacci spacer kit from Endless Bikes.
2.) 14T Kickass cog from Endless Bikes
3.) Spring-loaded tensioner from Misfit Psycles
4.) Single-stack BMX chainring bolts from Dan's Comp.
5.) SRAM PC-68 chain.

It was pretty easy dialing-in my chainline with the Fibonacci spacer kit. The first try, I was off by about 1.5mm. I simply added a 1mm spacer from the kit and was good to go.

The cog and spacers are beautifully machined and super-lite. The cog has a thick 1/4" base that sits wide on the freehub splines, preventing dig-in damage to the freehub body. Real quality stuff.

The stock 52T chainring and the 14T cog, along with the Primo Comet 20X1.35 tire gives me 68 gear inches, and 70 gear inches with the .5 inch larger diameter stock Kenda 20X1.50 tires.

The tensioner is only temporary solution until my SS wheel from Peter arrives (solid axle), wherein it is simply a matter of migrating my spacers/cog and tire.

The drivetrain rides silky-smooth, lite and responsive, and virtually silent. You can really feel the difference losing the cassette cluster, derailleur, cable and shifter make in the weight of the Swift. Makes it all the more easier boarding the commuter train with, and carrying folded through my office building. Not to mention, the bike accelerates and climbs quite well out-of-the-saddle. I might keep a 16T cog on hand for the days I want to ride the bigger hills, being that it is a snap to switch-out cogs with this system.