Let’s build a bicycle

Let’s build a bicycle

May 1, 2021 0 By Michael

I decided that I wanted to have another steel frame bicycle. The steel frame bike I currently own is a 1984 Raleigh Grand Prix, being that the bike occupies the bottom of the range from Raleigh it’s heavy and isn’t setup with nice components. I really want to ride one of the Eroica events be it in California or Italy or maybe somewhere else in the world. These events will take you through steep climbs, gravel roads, and beautiful views. With this in mind its time to start a new bicycle build. This time from scratch.

Material Selection

While I could scour the web and buy a bike to fit my desires, I really love learning new things and building things. To build the bike lighter than my current bike, I decided I needed to use some higher quality tubing. With that in mind I decided to use Columbus SLX. Columbus SLX was at one point their top of the line tubing designed for professionals. They basically took their Columbus SL tubing and added 5 ribs that spiraled towards the bottom bracket. These ribs occupy only a few inches, but were added to strengthen up the bottom end of the frame. Being that it was only designed to strengthen the bottom end, only the seat tube, down tube, and chain stays have the ribbing. All other tubes in the bike are Columbus SL. I purchased most of the tubing for this project from Ben’s Cycles in Milwaukee. https://www.benscycle.com/

Columbus SLX ribbing

When building a steel frame bike you have two options for joining the tubes. You could weld them, or you can build with lugs. I built the frame using lugs, since this is being built to look like a traditional 1970-80s bike. I bought the main lugs and the bottom bracket for the project from eBay. The seller had purchased the Lung Shen lugs from Nova Cycles. https://www.cycle-frames.com/ The dropouts, seat stay caps, brake bridge, and water bottle bosses came from Ceeway in England. https://www.framebuilding.com/ Other components and some of the materials for this bicycle build came from Framebuilder Supply in Portland. https://framebuildersupply.com/

Construction Method

When building with lugs the method for attaching everything is to braze them together. Brazing is a method which is also used by plumbers to attach copper pipes together. Basically you fit the tube/pipe into a fitting and fill any gaps with solder. To do this you must clean all your joints, add flux, bring the joint up to brazing temp with a torch and add your solder. The purpose of the flux is to remove oxides and to prevent oxidation during the heating process, thus promoting the free flow of the brazing filler metal.

Joint all fluxed up ready to be brazed.

The flux I used was Harris Stay Silv white. Because I was only brazing together the frame I only needed a MAP gas torch to heat my joints. If I was going to build the fork as well I would need a hotter torch. The torch I used is a Bernzomatic TS8000. While heating up the joint you are looking for a dull red color, and you have to keep moving the torch around the joint to not over heat one area. Once the joint is heated you can add the filler material. I personally used Harris Safety-Silv 56%. While adding the solder you have to keep moving the torch around the joint. The solder material will follow the heat of the torch allowing you to fill the joint completely with the silver solder.

brazed together joint

I gained the knowledge for this bicycle build by first reading all the way through Lugged Bicycle Frame Construction by Marc-Andre R. Chimonas. I then followed along his step by step instructions on how to build the bike. The information in this book was invaluable.