Saturday, November 22, 2014

Fork, Part 1

It's been a loooooong time.

Over the last couple of years, I finished the bike I was working on, made a sweet single speed, and rode them both a bunch.  I made a lot of progress with my brazing, but still count as a dangerous amateur.  

I've done a few practice forks, and I think this one will turn out well enough to bomb down big hills on.

First, I trimmed the fork down to the right diameter to fit the Llewellyn dropouts that I'm using.  Then I used my home-made blade bender to add a nice smooth bend.  The block was made for me by a coworker out of some scrap wood at his other job repairing boats.

I'm using 1.0/.66 True Temper blades.  As a Dangerous Amateur (tm), I really like these.  They bend easily and are pretty forgiving when I have to mess with them.  The folks at Henry James are always a pleasure to work with, and if I mess up I can get replacements pretty quickly.

48.5 mm rake on both blades, perfect!  The bends are also pretty close to perfectly in-plane.  Next step, fire!

For this bike, I have my own brazing setup.  It's oxy/propane, and the oxygen is drawn from the air by a medical oxygen concentration.  This way I don't have to deal with oxygen tanks or acetylene, and the slightly more diffuse flame that the propane makes actually feels a lot more natural for silver brazing.

I started by attaching the fork crown to the steerer tube.  I've gotten a lot more patient with practice and have stopped burning much flux.  I pulled through some excess silver, but a swipe or two with a stainless steel brush  while it was still hot got rid of most of it.  The rest should come off in a few minutes with emery cloth.

I didn't have time to start brazing the dropouts onto the fork, but I did spend a little time adjusting the jig.  I bought it from someone who'd already adapted it to accept an anvil axle, and with a few extra measurements, it turns out pretty awesome results.

Ok, it's been a while since I've written an entry, so I'm out of practice.  Please accept this blurry picture of a puppy I want to adopt as a show of contrition.

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