Tuesday, April 28, 2009
My Frame So Far: Photos from UBI Chromoly Brazing Class
Fork before assembly. Fork will be threadless, 1.125 inch, with flat crown, oval legs, and 40mm rake (which we achieve by bending straight blades). Not a traditional track fork, but close enough.
Fork in jig, after brazing, front view. Tips are brazed with brass; legs and steering tube are brazed with silver.
Fork in jig, after brazing, side view
Fork out of jig, after brazing, before finishing. Fork tip brazing is sloppy, so will require a lot of filing.
Head tube and top tube in Henry James jig, after brazing. Head tube angle is 74 degrees, but the frame will have a sloping top tube, so the actual angle between head tube and top tube is closer to 79 degrees. The lug set is called "slant six". Top tube is oversized: 31.8 mm.
Brazed front triangle, in Henry James jig. Note the head tube-top tube joint is fluxed -- prepared for re-heating to remedy a gap in the braze. Seat tube is 31.8 mm, and down tube is 36mm. So, this is a very oversized tubeset. All main triangle tubes are butted. I had originally gotten the miter angle on the downtube wrong, and I could not salvage that tube, so this is my second downtube. All miters (except the seat tube at the bottom bracket) were done by machine, with a Bridgeport vertical mill.