Exciting new skill set! Learning to design and TIG weld bicycle frames.
Bottom bracket shell welded to seat tube.
Using our 1:1 full scale, hand drafted template, tubes were selected for size and shape, then mitered and hand finished. Each tube is then laid out and verified for basic accuracy.
Bicycle frame welding is careful, precise work!
Most of the work in bicycle fabrication is in the preparation, including very careful mitering and fitting of the tubes before welding. The tubes want to fit precisely, without gaps.
Front triangle is tack welded together in the frame jig.
With the rear dropouts welded in place, the chain stays are placed in a fixture and mitered.
Tight fitting and carefully prepped miters are critical to a quality weld. It allows you to minimize the heat applied when laying your weld bead.
The tight joints at the chain stays and especially the seat stays are tough! You don't have a lot of room and if you didn't already, you'll certainly have a new respect for the guys who do this well. From a design perspective, this area is full of opposing priorities. If you want a big, fat tire in there, you need to move the chain stays outboard, but you don't want to get too close to the edge of the BB shell. If you need more clearance for your chainrings, you need to move the chain stays inward, but you don't want to get to close to the middle! You're miters will be extra tricky and it becomes pretty tight for a good clean weld. Of course the shape and size of the chain stays add a whole other element. Fun stuff!
Ideally, you have done a proper job up to this point and you won't have much cold setting to get good alignment. I'm quite satisfied with how straight my frame is at this stage.
Tacking on the disc brake hanger. I love a classic looking bike, but disc brakes do have some advantages.
Seat stays welded to the seat tube. These are the toughest spots to weld. Tight pockets and acute angles. For a first frame, I'm happy with how these turned out. Steep learning curve, but fun! I was sweating bullets to get these passes in without blowing through a tube.
Silver brazing of the seat stay bridge.
Completed 'cross frame! She's not pretty yet, but after some paint and build up, I'm looking forward to my first ride.
United Bicycle Institute bikeschool.com