OK, so I scored a frame and misc parts off ebay intending to build up a commuter off a CDale T400. Figured that with most of the parts off the auction and pieces I had kicking around, I could cobble something together. It was missing the shifter bosses off the downtube, so OK, let's turn it into a single speed. But I'm a cheap yankee bastard and was not about to go out to buy stuff like a cassette conversion kit or a freewheel, a chain tensioner, or any of that nonsense. This is how it came together:

T400.jpg

Still rough in this shot. I ended up replacing the front 26 wheel with a 700. And adding front brakes. And wrapping the bar. But that's about it. Here's a closeup of the rear:

T400 shifter.jpg

Like I said, I wanted a single-speed, but couldn't see shelling out the $20-30 for a singulator type of thing when I had a perfectly good chain tensioner built right into the derailleur that came with the auction.

You'd have to be pretty much a contortionist to be able to shift the thing safely on the fly. Other solutions that occurred to me included getting a longer set screw for the outboard adjustment screw and placing the der where I wanted it, or jamming the cable stop doohickey on the shifter end all the way to the der adjustment screw... except, of course, the der that came with it had the adjuster screw broken off. Or drilling a thumbscrew so it would work like a guitar string adjuster, with a locknut.

All of this a long way of getting to the point: is a bike set up like this a single speed? If not, what makes it not--all the gears at the rear? The derailleur? And if this isn't, then what about something like that white industries setup with the dual chain ring and dual freewheel setup?

Yeah, silly bike, absurd thrifty solution to a non-problem. But certainly a cheap way to get into riding a single speed. And being able to change ratios without a freewheel swap was a great way to find out what I like without resorting to multiple freewheels or chainrings.