Friday, May 28, 2010

Fork is Finished

Well, this is an achievement: the first bicycle element completed in the shop!

There is little to explain from today. I cleaned the inside of the crown (with my Dremel knock-off), fluxed everything, and set it up in Olivier's very nice fork jig. Then I put the whole thing vertically into the vise.

I brazed the joint complete in the fixture. For the front triangle, I'll only tack in the fixture, then align on the surface plate, then complete the joint in the vise. Since I don't have much of an alignment system for forks, I figured I would just braze it where it's straight—in the jig—and hope it came out straight.

The good news is that it was indeed pretty straight. And my filing of the Mafac bosses to provide clearance for the fork tang worked well, and I think it's pretty neat how that all came together.

But as the keen-eyed will have already noticed, I brazed the fork crown in backwards. I had filed the flat off the "front" of the crown but left this flat on the "back," since I was going to pass a generator wire through the hole. Well, you don't really need flats for generator wires anyway. This was the gods' way of telling me it would look better if I filed both front and back smooth. I realized the crown was backward as soon as I finished one side, so I filled the hole with silver, and when everything had cooled I filed it smooth. It now looks like this:

The Mafacs seem to sit pretty well on the completed fork—they'll just need a bit of filing/cold setting to have perfectly smooth motion. I'm pretty pleased with how that worked out.

I'm also happy with my shorelines, which came out very nice:

Most of all, I'm happy to have completed something! Thanks to Amir Avitzur for the Mafac bosses, to John Clay for the beautifully raked blades, and to Kirk Pacenti for the excellent Mitsugi crown.


walawalaoxenfree said...


Glad everything worked out.
The bike is looking great.
Wish I had the time to do the same.


AH said...

Thanks, Amir! Yes I'm lucky to have the time for all this.

Thanks again for making the bosses -- it's a real service to the classic bike community!