U.S. Built Custom Bicycles in Titanium and Titanium-Carbon Mix
Frame Welding: Still Beads Run Deep
The Seven weld bead may be the most misunderstood aspect of our work. It looks so simple, uniform, and beautiful (or so many people tell us).
Getting to this serene point began 35 years ago when Tim Delaney, Seven’s Lead Technical Welder & Teacher, developed the titanium welding techniques that most builders use today.
We’ve refined and improved our welding techniques countless times over the years. We’ve run countless in-house fatigue tests to enhance our weld durability and to ensure we thoroughly test any improvement concepts.
The weld bead beauty you can see is good; it is a sign of care and quality. The underlying engineering and testing you never see are what make Sevens tougher and truer than any other.
These images of Stef welding show a few examples of the intricate techniques we employ. During her nearly 30 years in the industry, Stef has welded more than 10,000 titanium frames, more than any other human. Regardless, Stef’s work is all about quality, not quantity.
As part of our Special Projects Team, Stef is responsible for welding Seven’s one-off SOURCE Endurance Race Gravel project bike, shown here. Seven’s special projects are frame designs that go beyond Seven’s already extreme customization. In this case, as relates to welding, the SOURCE project has tube interface geometry and tube wall manipulation we’re combining in new ways; it requires nuanced, self-aware welding skills. Stef is the perfect person for the SOURCE project.
Here, Stef uses a shielding technique to ensure zero oxygen contamination of the titanium weld. The inside of the frame is purged of oxygen, the backside of the weldment is protected from contamination by a shielding device, and the oversized torch cup protects the weld itself. These time-consuming techniques, along with a many others, are critical to providing the strongest, most durable weld possible.Stef, like all of our welders, focuses on one frame at a time. She will only work on the next project once she’s completed this frame. This singular focus helps build better bikes. There are no distractions and no conflicting information. We want our builders to focus on each frame as if it’s for a family member.Our welders use special titanium alloy welding wire that is more supple than the adjacent tube. This weld bead ductility provides increased strength and toughness. Additionally, we use three types of titanium weld wire, each optimized for specific methods of welding.Stef checks each frame on our granite surface plate, confirming frame alignment. She’ll repeat this check multiple times during the welding process to verify what she already knows: There is no straighter frame. Stef knows this because she follows welding techniques Seven developed over the past 35 years. We call this technique induction alignment; our use of welding techniques to achieve proper tolerances rather than solely relying on cold setting the frame after welding. Induction alignment makes the welds stronger and the frame straighter.We use a multi-pass weld technique. We don’t use pulse welders or other process simplification methods. There are no shortcuts to building the most durable frames available.
