While I was wrestling the Angel of Stupidity, deciding to mount my new fenders on the ‘wrong’ wheels, I did manage to remove the chain tensioner and rig up a “magic gear” that fits the chainstay length. I’m against chain tensioners. I think they’re inelegant and heavy (heavier than having none, at least), and the one I had only seems to work in an ‘outer’ position. It skips if you move the idler wheel inboard.
So I removed a link, and found a gear that works. I had to make sure my chainwheel was centered, though, since it was binding in one spot. I used the Sheldon method to center the ring – it worked perfectly, and was a lot easier than I’d thought. Surprisingly, it was the first time I’d had to do it in 12 years of fixed gear bike tinkering. Vertical dropouts. Go figure. I may go do it to the other 6 derailler-less bikes in my garage, though.
The 36×18 gear I chose (or that chose me) isn’t that useful for flat-land riding OR the super-steep pitches I want to ride. My plan to remove a link and drop 4 cog teeth don’t look like they’ll work. I put the cog on and wrapped the chain, but it comes a couple millimeters short meeting pin-to-pin. It might work when the chain wears more, or I could file flats in the axle, or get a cog FIVE teeth smaller, but I’ll probably just ride it like this for a while. 36×18 is a classic singlespeed gear, and spinning it does move the bike forward…
I am now looking for a 22t cog for a climbing gear, so I can re-dingle-ize the bike, but 22 teeth seems to be the point at which singlespeed cogs go couture and jump 10x in price. ~$3.50 for an 18t cog, to ~$30 for a 22t cog.