Today was a good day. There were no major screw ups, nothing was caught in an angry Bridgeport and torn up, no one hacksawed the wrong thing, all of our parts showed up (okay so maybe there was one screw up) and most importantly, I had a really good braze on one of my fork drop outs today.
My chain stays and dropouts rigged in the Anvil
I started the morning filing up my fork crown waiting for the day to get going. I am about 1/4 done with that right now. I hope to finish that, and the rest of the filing I have to do Saturday night after Doug’s Sabbith and the shop opens up again.
When things really got going today I spent most of my day working on dropouts. First off I had to remove a bit of length from the end of my chain stays so the plug in dropouts would actually plug in. After cutting and making sure they were square I could figure out where the tire would sit in relation to the seat tube and the dropouts. Then I figured out approximate chain stay measurements. This is where my bike will differ the most from a traditional road go fast machine. The normal chain stay length for a race bike is 415mm or so. I’m going more towards the sport touring side of things with 430mm chain stays. This will allow me a slightly cushier ride as well as a ridiculous amount of tire clearance for my horizontal dropouts. Even at 415 I would not have any problem clearance problems for the 700x23c tires I’m using, but I really want a slightly softer ride, even at the expense of some nimbleness.
So first off I stuck the chain stays in the bottom bracket socket, then plugged my drop outs in and slid a tire in to check clearances. I had plenty of room even with the huge 700×32 tire that I was using. The tire is way bigger than anything I will be using but worked just fine for a test fit. After I settled on a chain stay length I more or less made a note of it and will be trimming them to length next week.
Non drive side rear dropout after brazing and cleaning off flux.
Now it was time to get brazing. Doug has an Anvil fixture that I used to hold the dropouts and chain stays so that gravity could do most of the work for us. The fixture rotates and we made it so that the head tube would be facing way up in the air, and the rear drop outs were pointed at the ground. After mucking a bit with the fixture to get it to hold the dropouts in place with no gaps I fluxed up the joint, popped in a silver ring and was ready to braze. Since my dropouts are stainless I had to heat them up a bit more than anything I’d done before. Brazing stainless requires the metal to get hot enough to be a bit red before the silver will flow. Doug showed me how and after a small worry about why the silver wasn’t flowing down quickly enough everything seemed to work out. The tube was a bit scorched after I was done but is was nothing a little filing wouldn’t take care of. We repeated this process with the second chain stay and now I have rear dropouts attached to chain stays! I think the most difficult part about this was the height of Doug’s Anvil required me to crawl around on my hands and knees to braze the joint. I don’t think there is anything that can be done to fix that other than getting some crazy tall stand. Not the end of the world but did seem to make something that was hard to begin with a bit harder. Thankfully Doug talked / helped me through it and everything is cool.
The next task was to work on the fork. First off was cutting to length after raking (bending) yesterday and getting the dropout to fit in the hole in the fork. I’m using plug in dropouts in the front as well as the rear, so the process is similar to what I described above. After it was all fitted we put the fork in another Anvil (I think) fixture to braze. This fixture is way cool because it doesn’t require you to crawl around on the ground like the Anvill frame jig did. It plugs into a Park stand and away we went. The first braze went fine, a little more scorching on the fork blade but nothing to get two worked up about. I then went on to the second blade with Doug’s apprentice Herbie watching over me. This is the best braze to date. No scorching, fairly good shore line etc. This felt like a big win for me and that maybe I’m getting the hang of brazing. I was so pumped that it came out looking as good as it did.
Finally a good braze! Dropout on the fork.
I spent the rest of the afternoon starting to file down all the dropouts I’d brazed earlier in the day. Some think the filing is monotonous and repetitive, but I find I really enjoy it. I like it quite a bit more than brazing. I like the slow change that I can cause in the metal I guess. (edit: after brass brazing I’m not sure thats true anymore).
Filing one of my rear dropouts.
In the course of filing one of my rear dropouts I did find a gap. That was a bit of a bummer, but Doug said it was nothing to worry about and that it would be fixed in paint. Nothing structural so it will all be well.
The one fiasco of the day came when the lugs I ordered finally arrived. I’m using the Slant 6 lugs from Llewellyn. I didn’t realize that when I bought the lugs they were for double oversize tubing. This means that they fit around my head tube but none of my other tubes. Since I’ve planned to do a biliminate (chop off the ends of all the lugs so they are only “around” one tube) bike from the start this isn’t a huge deal except for the seat lug. Instead of the cool (and well finished, which means less filing) Llewellyn lug I’m going to use a Henry James lug on the seat tube. Not my favorite, as the Henry James lug is smaller than I’d like, but not the end of the world either.
There is still quite a bit left to do, and it sounds like as a class we’re at least a day behind where we need to be. Hopefully since all of our parts have arrived (Clifford’s stuff came today too!) next week will speed up a bit and we will get back on track. As for my immediate future there is lots of filing on the horizon. I’ve got to chop off the ends on all three of my lugs, this is done with a huge file and some grunt work. I’ve then got to finish the lugs to make em look pretty. I’ve also got to finish my fork crown so it can get brazed up on Sunday. The shop opens at sundown tomorrow night and I’ve got my work cut out for me.
Figuring out chain stay length.
Lots more pictures can be found on flickr.
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