Braided Downtube Frame

  Occasionally, someone will call the shop inquiring about “twisted downtube” frames, or a customer I’m building a bike for may ask if I’ll make one for the project. As much as I continue to enjoy forging and twisting steel, and have ventured even deeper into the dark arts of Blacksmithing, I no longer make twisted downtube frames. After many years of making twisted downtube motorcycle frames, before and after the passing of Larry, I feel that that design is very specific to Larry, and a certain moment-in-time, so I want to do something different.
  I had a customer come to me to build him a bike, and he wanted many of the traditional details he had come to know over the years. He liked the twisted elements, but was open to any new ideas too. This was an opportunity to explore other ways of treating the frame to give it a new look. What I decided was to make a single down tube section by braiding steel tubing and working the braided section into his frame that was under construction in the jig.

  I had the engine and tranny cradle already prepped on the frame table with the back bone and neck in place. I had an image in my mind of what I thought the braid should look like, but didn’t decide how to do it till I lit the torch. After cutting my 3 sections of tubing, I lined them up vertically in the vise and started heating. I chose tubing, instead of solid rod, for the superior structural rigidity, but had to be extremely careful not to kink or collapse the tubing. As with any forging process, decorative or practical, timing is everything. I had to decide, in the first few minutes, how I was going to start my bends, then continue with that pattern all the way to the top without stopping. Basically like braiding hair, but upside down.

  After the braided section was complete, I corrected any straightness issues, and planned how to merge it with the mainframe. At the neck, one leg rolled back into the gusset while the other two wrapped the neck like a choker. At the bottom, all three legs swirled around the frame tubes engaging solidly.

  Once the assembly was complete, I TIG welded the entire braided section with Silicon Bronze to fully engage every intersection. Initially I had TIG welded all the joints with steel rod, but in the end, I really wanted that honey-dipped, brazed look that seeps into all the seams. On steel, I prefer using the Silicon Bronze to achieve this, instead of brazing, for a cleaner more controllable result.

  After days and days of sanding and shaping every joint, I had the frame brass plated, then I oxidized it to a dark patina. This process gives great contrast to the finish when it’s re-polished.

  I love obsessive details and experimentation, but this is something I don’t plan on doing every day. It’s a challenge, though, to work steel like taffy and still create a stable platform upon which to build a motorbike...