Another winter, another project bike, and this one with a very simple drivetrain. Yep, a one speed.
Why a one speed?
It’s simple. A single chainring, a single freewheel, and an endless chain connecting the two. The only things simpler: 1) a fixed-gear setup–one gear, but no coasting, and 2) a direct drive as found on a child’s tricycle or old-fashioned highwheeler.
It’s elegant. It’s hard to exaggerate the impact of the chain drive on bicycle design. If you commanded a highwheeler/ordinary/penny farthing bike with a 50-inch front wheel in 1891, you could ride 10 mph all day on smooth roads, assuming you could find smooth roads. If you pedaled a safety bicycle with equal-size tires and chain drive in 1897, you could go just as fast or faster–without worrying about flying over the handlebars on a rough stretch of ground. And if you had a bicycle with a chain drive that incorporated a freewheel in 1910, well, you could fly down hills with your feet resting serenely on pedals attached to non-whirling-out-of-control crank arms.
It’s appropriate. I built this bike for an 18-mile commute on the Rock Island Trail, starting and ending at the library in Dunlap. The trail has its ups and downs but it’s relatively flat and mostly protected from the wind, which favors the one-speed approach.
It’s a challenge. Not a challenge to ride but a challenge to build. This particular bicycle frame, like most frames built since the 1990s, features vertical dropouts–the rear axle slides upward, not backward, before being secured into place. The advantage of the design is there’s no way for the axle to slip forward under load. The disadvantage is there’s no way to tension a one-speed’s chain without a derailleur or chain tensioner. You need just the right chainring/cog combination if you’re going to keep it simple, unless, perhaps, you use an Eccentric Eno hub like I did in 2013.
It’s compatible. Modern multi-speed drivetrains work best when the parts all come from one manufacturer. But a one speed works fine whether or not all the parts share the same name. It doesn’t matter whether the components are new or old designs, either. The crank on my bike came from the 1990s. The chainring, chain and freewheel are from the current century. Not sure, but the incorporation of such disparate technology may make me a Time Lord.
It’s light. No front or rear derailleurs. No shifters, cables or housing. One chainring and shorter chainring bolts. Up to twelve fewer cogs (remember, Rotor makes a 13-cog cassette) in the back. The chain is as short as it can be. What does subtracting all that stuff add up to? Less weight. Less maintenance. Less…stuff.
It’s what Alexandera Houchin rides. In 2019, Alexandera won the women’s Tour Divide on a one-speed Chumba Stella Titanium she pedaled through the Rocky Mountains from Canada to Mexico. (When she’s not racing, training, studying or working, she writes a blog.)
It’s a reminder. When you were a kid, this was what you had. A one speed. And you were thrilled with it. You could move three to four times faster and farther on a bicycle than you could on foot.
By the way, you still can. And if, say, the Greenway bridge over Knoxville Avenue in Peoria feels a bit too steep on a single speed, do what I do. Lean forward and get out of the saddle.