Right Stay

I started on the rear triangle on Sunday!.  My strategy is to get the right side just where I want it, then I can put a wheel/rear triangle t-square in it to properly align the left chainstay.  I'm mostly going at it this way because my homemade jig doesn't keep the dropouts lined up perfectly, and the extra steps let me tweak it on the fly.

The dropout went on easily.  I used some more of the 50N silver; I think I'm starting to get a better feel for it.  It certainly seemed to jump when I wanted it to.

I pinned the bottom bracket in the jig using the square profile nails that Cycle Design sells, then brazed it freehand.

The one issue I noticed was that the pins wanted to draw the stay up just a little bit from how it fit in the Jig, so I used the sophisticated method pictured above the add a little weight to the end.

Here it is, brazed and soaked.  On this bike, I've left all of the bottom bracket miters a bit long., with the intention of grinding the inside smooth when I finish.  

As a bonus, here's a picture of my cable routing:

Crossing the cable from the right shifter to the left side of the down-tube (and the left to the right) keeps the housing from having sharp bends, but looks a little odd since the cables must cross back under the down tube.  I spent a little time with some stainless tubing to solve that.  It's silly, it's overkill, but I like it.  This way the correct cable goes to the correct shifter, but the cross happens out of sight so the cables will stay roughly parallel to the down tube.  As it turns out, this stainless steel ball of spaghetti creates very little friction.

For the curious, here's the great Sheldon Brown's take on crossing the cables.  To keep things balanced, here is an opposing viewpoint.

Also worth noting, I've drilled the bottom bracket for drainage.  Almost all water related damage that I've seen or heard of on a bike was the result of standing water, not just exposure.  Hell, I've been riding my first build, sans-paint, in the rain on and off, for years and the rust hasn't made any real progress.  Since I can't totally seal this area (there's always the potential for a little water to sneak in through the seat tube), I wanted there to be a good way for it to drain.

Fork, Part 2

Had some time to work on the fork this week.  The fit up on the crown was a bit on the gappy side, so I went with 50N silver instead of my customary 56%.    

56% flows faster, melts at a slightly lower temperature, and I just generally love working with it.  

50N is a bit thicker, and a bit more sluggish.  It has a few advantages: it will fill larger gaps, it will form small fillets for strong joints on brake bridges/other high stress braze-ons, and I'm told that it wets out more easily on stainless steel than some other silver alloys.

The downside is that I just haven't gotten the hours in with it to feel totally confident when it's necessary.  I ended up doing a second pass to make sure I had good penetration, and definitely crisped some flux near the end (should have let it cool down and re-fluxed it instead of heating it right back up).

That said, I think I'm going to stick with this one.  I was able to draw the silver through to the pins, and I think it's unlikely that I have a bad fill.

Here's the crown all cleaned up.  I love Henry James' crowns, they have this beautiful elegance to them.  I can't wait to see it with some paint on it.

I also love hourglass spindles.  I set these up to work with Nitto/Rivendell's Hub Area Rack.  It's a gorgeous piece of gear.  I can't imagine actually needing four bags for the kind of riding that I do... but WHAT IF? 

Worth mentioning: I used 50N for these rack mounts too.  Note the nice little fillet around the base of each of them.  

Here's the whole thing.  It needed a bit of a twist, but I've gotten it pretty straight. 

Bonus image: my co-blogger, Gimble.  She gets her own chair.

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.