Welcome to the second installment in Paul Brodie’s framebuilding dissertation, where he recreates a Whippet full-suspension bicycle frame from 1888, which will be presented at the 2012 North American Handmade Bicycle Show.
“I call this part of the Whippet the ‘Front Linkage’. The pivot is wide, because it has to keep the seat tube from rubbing the inside of the rear stays. I can’t really call them seatstays, because they don’t attach to the seat tube. The Front Linkage was a bit of a challenge, and I enjoyed making it.
I machined a short tube in the lathe, and then filed a curved outer surface so it looks like a casting”.
“Here I’ve setup a little bending fixture in my vise. The rod is 4140 machined at a 2 degree taper, heated red hot, and bent to a right angle”:
“Because I tapered it from big to small, the end of the now bent and tapered rod is still perfectly faced, and sits perfectly on the tube’s spot faces for TIG welding”.
“After TIG welding, it reminds me of cattle for some reason…”:
“Here it sits over the frame tube, positioned for TIG tacking, using spacers and masking tape”.
“Right after fillet brazing, still quite hot”:
“After cooling slowly, the flux is soaked off with hot water”:
“A little bit of polishing… no problem”:
The drawing below is one of Paul’s references for The Whippet rebuild, which should give you a fair idea of his expertise. Stay tuned for more updates on the project, leading up to the NAHBS on the 3rd and 4th of March in Sacramento, where the finished bike will be exhibited.
Paul teaches Framebuilding 101 at the University of the Fraser Valley. For more information on the course, where you can learn how to build a steel framed bicycle using Paul’s original jigs that have built over 4000 frames, visit the UFV website.