Building My First Bicycle (in 12 Days) Framebuilding 101
For the past five years I've been riding a Trek District belt-drive bicycle as my primary mode of transportation around Chicago. An unfortunate frame failure last January took the Trek out of commission and put my Surly Long Haul Trucker (LHT) in the position of being my main bike. While I loved the LHT for carrying heavy loads home from the grocery store (and riding to Canada), I really missed the simplicity of having a belt-drive single-speed to get around Chicago.
After finishing my MBA at Depaul, I was suddenly faced with having some free time and started investigating the possibility of taking one final 'masters' class -- but this time in framebuilding. Having recently written a business plan for Chicago-based bicycle manufacturing, I was keenly aware of the established builders, and sought out Levi Borreson of Legacy Frameworks to see if he'd be available to share his tools and expertise so I could build the ultimate urban commuter from the ground up.
A couple of email exchanges later I was sitting across from Levi at a table in the Chicago Sustainable Manufacture Center (Bubbly Dynamics), located in the Bridgeport neighborhood. I came to the initial meeting with a rough concept for the bicycle I wanted, complete with geometry, and Levi helped me with the process of transferring that idea into reality.
Seeing that I was coming into the build process with minimal prior metalworking experience, a lugged steel frameset seemed to be the perfect base for the ultimate commuter bicycle. After discussing the merits of the various tube sizes, dropout options and project goals, we choose a set of Columbus Life double-oversize tubes and a Llewellyn lug set from Nova Cycles Supply to be paired with Rocker dropouts from Paragon Machine Works.
With the geometry decided and materials selected, we transferred the rough design into BikeCAD to make any final adjustments and accommodations. The BikeCAD design would ultimately serve as the blueprint for the build portion of the project.
During our first actual day in the shop, Levi walked me through the basics of brazing. Armed with a torch powered by a mix of propane and oxygen, my first task at hand was to pull silver solder through a ring of metal slid over a steel tube.
The second (and more difficult) brazing test was to take a bronze rod and turn it into a stacked tower on top of a piece of steel. During the construction of the frame, we'd use bronze, silver and Filet Pro solder, depending on the application.
While build day 1 was essentially a primer on metalworking, I couldn't resist dry-fitting the fork materials together to see what was to come.
Day 2 started with the transfer of the BikeCAD design for the fork onto a life-size cardboard template. With a dummy axle inserted in the dropouts we were able to measure and mark the tubes so they could be cut to length and mitered.
With the tubes cut, the fork was placed in a jig and tacked to ensure the correct angles would be maintained through the brazing process.
Day 2 wrapped up with the fork dropouts being attached to the legs.
After soaking the fork to remove excess flux, it was over to the bench to do some clean-up work using a combination of hand files and a belt sander. As I would quickly learn, there is an incentive to be precise with the torch, and solder as clean-up work can take some serious time. Once the clean-up work was done, a disc brake mount was attached and the fork was done (minus some additional clean-up work to do).
The fourth day started the build of the main triangle of the frame. After transferring the BikeCAD blueprint to drafting paper and double-checking the measurements it was time to visit the mill. We clamped a tube block to the down tube, used a digital level to make sure everything was square, and with a hole saw blade in the mill, cut the tube so it would sit flush with the head tube. This process would be repeated for the top tube and seat tube, with a mitered cut being made for the down tube/seat tube junction. Day 4 ended with the main triangle being tacked into place on the jig so it would be ready to be brazed the following day.
With all of the joints covered with flux, day 5 was spent brazing the main triangle of the frame.
The progress of the build process was ideal, as each day built on the skills learned from previous days. The task at hand for day 6 was to get the rear dropouts built. We transferred the rear triangle BikeCAD drawing to drafting paper to map out how the chainstays will attach to the end-caps and the end-caps will attach to the dropouts.
Day 6 ended with the bullet end-caps being slotted and brazed to the dropouts. Day 7 began by cleaning up the connection and getting the stays ready to attach to the bottom bracket shell.
Day 8 is when it finally starts to look like an actual bicycle! One of my design criteria was for a solid connection between the seat stays and seat tube, as I've always disliked the appearance of stays that appear to be minimally tacked. Little did I know that fabricating and attaching the seat stay caps would prove to be the most difficult part of this project. I left day 8 with a sense of dread that I'd bitten off more than I could chew and afraid that I'd come to regret the fancy seat stay attachments I so wanted.
Day 9 put the finishing touches on the frame by attaching the cable guides and bottle cage mounts. The day was capped off by spending hours with a file in hand and cleaning up the excess solder from the connections made over the prior 3 days.
After a considerable amount of time filing and filling the seatstay end-caps, my earlier worries started to subside. If there was ever a time in the build process that I was glad to have Levi standing by my side, this was it! With a number of joints in such close proximity, this phase of the project really benefited from having a skilled hand to help ensure that stays attached as initially envisioned. We capped the day off by facing the headtube and bottom bracking, reaming the seattube and machining the forkrace on a lathe in prep for the headset race installation.
A handbuilt bicycle wouldn't be complete without a nice set of handbuilt wheels to go along with it. Working at home in front of the fireplace was quite the scenery change from the warehouse in Bridgeport. The front wheel is using a Sondelux SL hub which will power the headlight and taillight though an integrated connector in the fork blade. The rear wheel is using a Hope Pro 2 Evo Single Speed Trials hub to attach the Gates Carbon Drive belt-drive system.The rims are Velocity Aileron disc-specific tubeless rims in the polished finish (I wanted the reflective version but unfortunately they were out of stock).