An obsessive breakdown of my custom fixed gear bike.
A few years ago I decided to build a custom fixie. I love fixed gear bikes because they’re simple, light, and easy to operate. I also like customizing things, and the idea of building a bike that perfectly fits my frame/lifestyle was too tempting to ignore.
My vision was based on a white frame and glossy black crankset, so a storm trooper immediately came to mind. Although I’m not really a Star Wars fan, the analogy worked since I also wanted something suitable for an urban setting — something quick, rugged, and comfortable in an urban setting. All the original parts were selected accordingly.
Over time, I’ve experimented with various components based on what I know about the materials most commonly used. For example:
- Steel is the least expensive material. On the plus sides, steel is both strong and supple. “Chromoly” steel, which is a mix of chromium and molybdenum, is great for bike frames since the material soaks up bumps and harsh vibrations. Damage is less of a factor too, since steel tends to bend or deform under extreme forces. On the down side, steel is also heavy as fuck, being about 2.5x denser than aluminum. This is why there isn’t a steel component on my bike, aside from a few nuts and bolts.
- Aluminum is about twice as expensive as steel, but it’s super stiff and weighs a lot less. The higher the quality of aluminum, the lighter and stiffer the component. However, aluminum is easier to damage than steel, and will crumple like a soda can when it fails. Also, it’s the least comfortable material since bumps and vibrations aren’t dampened like they are with steel.
- Carbon fiber is a really interesting material. It provides 2-5x more rigidity than aluminum or steel at a fraction of the density, meaning that carbon fiber is feather-light and stiff as hell. More importantly, carbon fiber absorbs shocks better than any metal. But two things make this material less attractive: it’s incredibly expensive, and shatters completely when it fails.
- Titanium is another nifty material. Although it weighs a bit more than aluminum, it’s still only half the weight of steel while being just as strong. Titanium frames and other components are hard to find and crazy-expensive, but it’s commonly used for high-end saddle rails (which often accounts for most of the overall weight of a race saddle).
As I rode in different environments or on new surfaces, I found ways to tweak my set-up for improved performance and/or comfort. For instance, the original aluminum bullhorn handlebars looked cool, but they ruined my lower back. So, I’ve since upgraded to carbon fiber riser bars, which are lighter, absorb harsh vibrations, and reduce strain on my old man body.
At this point I think I’ve finally ended up with a result I’m really proud of (and love to ride). Below are all the parts used in the bike pictured here, and why they were chosen in case you’re thinking of building a custom fixie of your own.
Frame, wheels, and drivetrain
Since I couldn’t afford a carbon fiber Cinelli, I opted for an aluminum frame from Pure Cycles instead. The Pure Fix Keirin Pro Frameset is double-butted 6061 aluminum (with beautiful welds, I might add), and sports a carbon fork with an integrated headset. Pure Cycles only had a 52cm version in white at the time of purchase, which admittedly is kinda boring. But it was lighter than steel, stiff as hell, and therefore super responsive.
From my past experiences riding a fixie, I knew that the crankset and bottom bracket had to be tough enough to withstand the forces of hard pedaling. In my opinion, the only option for a fixed gear bike based on a track frame is the SRAM Omnium Crankset. It’s strong as fuck and looks awesome. Sure, it might be on the heavy side at 825g, but it absolutely will not fail.
To pair with the frame, I went for the Pure Fix 700C 30mm Machined Pro Wheels, also from Pure Cycles, featuring sealed baring hubs in white for fast, smooth rolling. Attached to the rear wheel is a heavy-duty Shimano Dura Ace fixed gear cog. Together with the crankset and a heavy duty chain, the bike would have a drive train capable of standing up to any abuse.
Obviously, wheels are useless without tires. I wanted a durable racing tire that was lightweight. That’s why I wrapped the wheels in Continental Grand Prix 4000 S folding tires and Supersonic inner tubes, which together save about 100g over standard wheels and tubes.
There was still one more set of components most people seem to forget about: the pedals. Other bikes I’ve ridden with small, cheap pedals were hard to find with my feet when starting off, and even harder to keep planted when traveling briskly. After some agonizing, I settled on Atlas pedals from RaceFace. They’re generously sized and yet have a slim profile (so as not to scrape the pavement when leaning into a turn).
Stem, handlebars, and brakes
The Atlas pedals are actually intended for mountain bike applications. This got me thinking: Mountain bike parts are built for strength and durability, which led me down the path of creating a hybrid track bike with off-road ruggedness. So, I chose the EC90 SL carbon stem from Easton, which is intended for mountain bike racing applications.
Next up are the handlebars. As previously mentioned, the original bullhorn bars were brutal on my back, and made riding anywhere tedious. The WCS Rizer Carbon Handlebars from Ritchey are so much better. At 710 mm across with a 15mm rise and 9-degree sweep, I have more control and my back is infinitely happier. Plus, the fact that they’re carbon fiber means they only weight 180g and absorb vibrations better than alloy.
The purist in me would prefer to ride with no brakes at all. But in a city like San Fransisco or Berlin (where I currently live), brakeless bikes are a liability. For minimal weight penalty and enough stopping power to get the job done, I fitted a SRAM Rival brake to the front wheel only. (I couldn’t find a lever that fit the handlebars, but my bike mechanic found an unbranded used one in storage.
Seatpost and saddle
What goes best with carbon fiber handlebars? A carbon fiber seat post, of course! In combination, the vibrations communicated to sensitive contact points are wonderfully dampened, and create a smoother, more comfortable ride on any surface. The one I use now is a Ritchey Superlogic Carbon One-Bolt Seat Post with a 25mm offset.
About that offset. Not only does it allow for a more relaxed riding position, the “bent” end deflects harsh bumps and annoying vibrations away from my buttocks (as opposed to straight up my asshole with no setback). But I diverge…
Atop that beautifully sculpted seat post sits an SLR saddle from Selle Italia with titanium rails. I picked it mostly because it was the lightest thing I could find in the bike store at the time, but fortunately it looks fantastic with the seatpost.
Bits and pieces
There are a few other little details I thought about as well:
- For the break line, I used a Road Elite Sealed Brake Kit from Jagwire
- Carbon headset spacers from Ritchey were added to increase handlebar height
- Theft-resistant wheel nuts from some Japanese manufacture I can’t remember
- Aluminum Presta valve caps that can’t be easily broken or stripped
- Fuxon MTB grips complete the mountain bike aesthetic
It’s definitely not a classic fixie. However, it is supremely strong, fast, responsive, and handles paved surfaces like a champ. I can also cruz along at a lazy 4 kilometers per hour in comfort, or carry it on my shoulder easily when confronted with steps. Considering the intended application in mind, the end product is fucking amazing. Oh yeah, and it only weighs 8kg!
I love my bike, and enjoy the thought that there’s nothing else out there quite like it 🙂