The Making of a Single-Speed: Part 2

I've got a pretty decent stockpile of parts kicking around. When it came time to choose a crank for this bike, I considering improvising a solution using some low end stuff I'm never going to use, but nothing really seemed up to my standards. So instead, I decided to go with this half-decent Sugino I got at the Portland Bike Swap. I only paid 2 dollars for it due to some pretty heavy but largely superficial wear. Anyway, I stuck them on the bottom bracket and this happened:

Note the distance between the chainring and frame. Now, there's nothing about this set up that's technically wrong, but for our purposes, we want to close up that gap as much as possible (I'll come back to the "why" of this a little later). Note how there is an impression in the frame to make room for a really close fitting crank. The goal is to move that chainring as far in as possible.

These are bottom bracket spindles. The one in the middle, I believe, is the one that we just had the cranks mounted on. The other two are spares I had lying around. The goal was to find one that was notably shorter than the others. Unfortunately, these were all pretty close to each other. So I went down to my friends at Port City Bikes and bought a new spindle that was basically as short as possible. Here are the results:

Compare the first photo to this photo. That chainring is now basically as close to the frame as it will get without rubbing. This not only looks pretty cool, in my opinion, but it also serves a purpose. You may remember in the previous post that the back wheel's hub was spaced very much off center. What that means is that in order to have a perfectly straight chain-line, we needed to get that chain ring as far to the left as it would go. And we got lucky...

Perfect! It's not always easy to make the chain perfectly straight like this. Many times, it requires the rear wheel to be respaced and "redished", which requires wheel truing skills that are not my strong suit. This time, we lucked out and the shorter bottom bracket spindle was all it took.

Because this bike is to be ridden by somebody who hasn't been on a bike in years, I deemed the drop bars unacceptable. Instead, I threw on these upright "three-speed" style bars I had lying around. Much more comfortable for casual riding. The brake levers were purchased at the Orono Bike Swap for $2.50. They appear to have, at one point, had shifters built onto them that were ground off. The price was right, though. It should go without saying that these bars will be equipped with grips, I just need to buy them first.

The (nearly) finished product.

Bike: $25

Handlebars: $13

Brake Levers: $2.50

Brake Cables: $4

Crank: $2

Bottom-Bracket Spindle: $10

Pedals: $5

Chain: $12

17t Freewheel: $15

The Making of a Single-Speed: Part 1

Like many other things that people are often afraid to repair or modify on their own, bicycles are often thought of with an undue level of mysticism. It is true that there are complexities in a bike's workings, and they are not without their little counter-intuitive bits. For the most part though, they are the same as any other piece of machinery in that the best way to figure them out is to just senselessly tear into them until you get stumped. That's basically how I learned, and how I continue to learn about these things.

Of the many projects on my plate right now, one of them is this cute little Univega, that I intend to build for my girlfriend. Having not been on a bike in a long time, she requested that I build her a single-speed so that she wouldn't have to worry about shifting. As a very enthusiastic fixed-gear bandwagon jumper, I am very happy to oblige.

So how does one go about converting a 12 speed road bike into a single speed? Well, it's not always necessarily an easy job, but it is essentially pretty simple. First thing's first:

See all this junk? This is a triumph of technology beyond what anyone could have conceived of in the early days of the bicycle. Basically, we need to destroy it.

The cone shaped thing covered with grease and teeth is called a freewheel. This particular one has 6 gears on it and it threads directly onto the hub, like a giant, violent, ratcheting bottle cap. At some point around 1990, the industry switched to a different system using "freehubs" and "cassettes". In either case, having several gears on the back is less than advantageousness for our purposes, so we need to unscrew it using some very specialized tool that you probably don't have any reason to own, unless you're like me and you've done this about a billion times. The little dangly thing is called a derailer, and we don't need that either.

Similar to our problems on the rear end, this guy up front is also a little overambitious. This is called a crankset, and more specifically, this one is a double crankset. That means, as you can hopefully assume on your own, that it has two chainrings, which further allow the rider to adjust his or her gear ratio on the fly. We don't need that. Technically speaking, we don't need to replace this part. I've built single speeds with double and triple crank sets before, simply by removing the front derailer and only using one chainring. However, that always looks pretty ghetto, and we don't want my girlfriend looking like a fool on a bike I'm building for her. She's too classy for that. So yeah, say goodbye to this crank.

Shifters? Pfff.

AFTER PHOTOS

As you can see, the 6 speed freewheel is gone. Our next step will be to thread on a single-speed freewheel, which is essentially the same kind of part, but with only a single gear on it. However, as the bottom photo reveals, we have yet another step ahead of us. Because the original freewheel was so wide, the hub is spaced far to the left to accommodate it. Our new freewheel will be much smaller, and won't need as much space. In addition to that, the new freewheel will want to be much further to the right than this set up currently allows, in order to keep the chain going in a straight line... We will deal with this in the future.

The crank arms are now removed from the spindle. The part that's now left, including the spindle, the bearings, and the associated hardware, comprise what is known as the "bottom bracket". This specific bottom bracket may also need to be replaced in the future depending on which crank is mounted to it. Spindles come in different lengths, and it may be necessary to have a more narrow one in order to keep our chain going in a straight line.

This is a wide shot of the bike with all the unnecessary parts removed, including the shifters, derailers, cables, and a few clamp on cable stops. The kick stand remains, for now. I always ditch kickstands on my personal bikes, but sometimes other people like them, so I'll leave that as an option for now.

These are all the parts that were removed in this phase of the conversion. Of these, the only parts that will be replace are the crankset, the pedals, the chain and the freewheel. All of them will be more lightweight equivalents than the ones in this pile.

Stay tuned for the next step... when I find enough money to make it happen.

The past few weeks have been an exciting time in Bike Land. Today was the Orono installment of the Great Maine Bike Swap. I had initially intended to leave with just a handful of parts and call it a day, but that didn't exactly work out. I'll keep this simple:

My 1962 Raleigh Lenton Sport

This thing hit me in waves. I don't recall what exactly it was that struck me first, but once this bike grabbed my attention it didn't let go. There is an article about these things on Sheldon Brown's website, but allow me to break it down for you in in accessible terms: This thing has a very serious case of old. Though the numbers stamped on the rear hub suggest this to be a 1962, the design of this bike is based on conventions dating back to the 40s and 50s. The weird stubby stem and vaguely track style drop bars are the first tell, and from there, it just keeps going. It's not too too uncommon to find an old bike like this, but to find one in ridable condition, and with all it's parts and accessories intact, well, that's something special. Especially if it costs 25 dollars. Hell yes.

Original Brooks saddle in what I would consider to be fair condition. Definitely capable of restoration.

This bike is a three speed, with a Sturmey Archer TCW hub featuring smooth internal shifting and a coaster brake. Internal hub shifting has a mixed reputation, but I'm a long time fan. They require almost zero maintenance, give a simple but usable range of gears, and maintain that smooth simple chain-line I've come to love.

...Also, those plastic fenders are probably worth something on their own.

Univega Nuovo Sport

Not much to say about this other than that it is fodder for a project. It's a nice bike that's a few sizes small for me. Aluminum rims, centerpull brakes, forged dropouts, and a drive-train that is soon to be tossed into my spare parts bin.

That isn't all of it, but it does complete this post. I also acquired a third bike and a handful of parts. All in all, a productive day that has rendered me fairly poor.