Sheldon Brown had some truly unique bikes. However, I think his fixed/free mountain bike is truly Blue Collar. If you have an old mountain bike lying around, it could be a fun project to spice up that local trail you’ve ridden hundreds of times.

My Hercules has a 165 mm Shimano 105 crankset, with 52/42 Biopace chainrings. It has a 52/18 fixed gear, which is what I use most of the time. If I flip the rear wheel around, I have a 52/20 freewheel gear, good for longer or hillier road rides.

The most unusual feature of this bike, however is that it has a 2-speed freewheel, with a 30 tooth sprocket as well as the 20. The crankset has a 42 as well as the 52, and I can change gears manually, much as the speeds are changed on a drill press. The 42/30 gear is the off-road combination, and makes a pretty good general purpose gear for the local singletrack.

One of the first things that struck me was, I wonder how many people would tell you that you can’t run Biopace chainrings with a fixed gear? Mr. Brown would just go for it, if he thought it could be done. I’m not sure they always should be done though, the Bianchi Osprey at the bottom of the page seems rather sketchy.

I often take my single speed out for club rides, as they tend to be a bit slower. A bike like Sheldon’s would be great, with the fixed gear being a true challenge with the ability to switch to a single speed if you fall too far behind. It would be a fun bike for riding with beginners.

Oh yeah, dig the wood grain.

Link to the page, “My Fixed/free 1-speed/2-speed/3-speed Mountain Bikes” from sheldonbrown.org.