I completed the fork today! Unfortunately, I didn't take a picture of it at any point. But, take my word for it, it's done. There wasn't a ton of work left to do on it, anyway, I only had to braze the brake bosses to the fork blades. Koichi set up the bosses on a jig that could bolt onto an adjustable t-square and hold them in place during the brazing. He set the position based on what he knows about where brake bosses ought to be places for a given wheel size: in the case of cyclocross bikes, at 27.0cm from the center of the axle, I believe. With the bosses set in the jig and covered in flux, I brazed around the seams with 50N nickel-silver brazing alloy. Strong and easy. The fork is going in the hot tub tonight to dissolve the flux and come out shiny and ready for finishing.
It looks awesome, as a straight-blade cyclocross fork should.
The Frame
The frame is getting close to done, too! The main work today consisted of upgrading all those rear triangle tacks to legitimately brazed joints. Out of the jig, the frame had to be kept in relative alignment throughout the brazing process, which was done with a dummy rear axle and a homemade aluminum alignment clamp that held the down tube, seat tube, and seat stays in place. I first worked on brazing the chain stays into the bottom bracket shell lug, which proceeded very much in the same fashion as the seat tube and down tube. We used 56 nickel-silver alloy for that, I think... Then, I brazed the seat stays to the seat lug, which was actually really fun. For one, it dealt with the fastback seat lug design - my fave - and, for another, it meant making cute little brass fillets, which came out really well. So it was pretty darn satisfying. Finally, I brazed the rear dropouts into the stays. LOTS OF WORK. Again, working with the density differential of the dropouts and the stay ends was very difficult. Furthermore, it wasn't just a matter of tacking, but rather filling the ends of the tubes in a clean and controlled manner. "Clean" and "controlled" are probably generous adjectives to describe how I got those monsters to stay in, but stay they do.
In the jig.
Showing me how it's done.
The fork and the rear triangle took until about 4:00pm to finish. In the last two hours I brazed on the cable stops (two triples on the top tube, a single on the seat tube, and two singles on the right seat stay à la cyclocross cable routing) and mitered a seat stay bridge. There won't be room for a chain stay bridge since, though the extra stiffness and strength would always be nice, the interrupted clearance could mean clogging in cyclocross or otherwise nasty applications. For the little braze-ons, we used what Koichi calls a Brazing Buddy, which rests on the tube and holds the small little miscellaneous braze-ons in place. I'll snap a picture of one in action tomorrow, since the other Sam in the class has all of his braze-ons yet to attach. They're really tricky, finicky buggers, with their tendencies to slip out of alignment and/or fall off as the flux liquefies. The Brazing Buddy helps, but doesn't solve the problem. Or maybe my Brazing Buddy and I aren't close enough to make those judgments yet - I probably don't help it much either. We used 50N nickel-silver for all the braze-ons thus far, since the cable stops undergo some serious forces.
All my little braze-ons. They're really cute in their bowl.
The charred thing is a cable guide. The dropouts were tough.
That's the gist of it today. Tomorrow will be similar, with less brazing and more finishing. It'll also be our last day. I'm bringing cinnamon rolls for breakfast for everyone. I like celebrations, and this has been a very significant and meaningful item to cross off the bucket list. *Definitely more instructive than college. Meditations to follow, undoubtedly. But don't get your hopes up for more from me tomorrow. I'm on PermaVacation, after all, and will be heading to Moab for a long weekend with my BFF, then maybe checking out Mr. Ferris' operation at Anvil Bikeworks next week. We'll see what happens; unemployment can be quite freeform.
*Mom and Dad: Ha-ha, I kid, I kid!
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