Summertime and some thoughts

Well, now that the cargo bike is off to bosun's house and has been riding around town, i took a little time to ride bikes instead of build them. work at the shop is pretty busy, as per usual this time of year, and it has been nice to explore my surroundings a little further afield. in addition to riding bikes and working on bikes, i have been doing a lot of reading on the internet about and amongst frame building people. although i hesitate (as will become clear) to jump into conversations being held by veterans with hundreds and hundreds of frames under their belts, i did have some things to say. frame builders are a famously grouchy lot. gruff, reticent, hermit like, etc. lots of dudes (mostly dudes, white, sadly) who spend a lot of time in garages or garage-like spaces performing amazing feats of creativity, engineering, production, and design. the internet conversations of these people is fascinating and rich in helpful material for newbies like myself. however, it is not very welcoming at all to the newbies in several ways.

first, you have to kiss the ring of whomever you want to acknowledge as your personal frame building idol. there are a couple of choices as far as that goes. next, you must not cross one of many very thin lines in the sand. your ideas, however good you think they are, probably aren't that great. while often this is true of relatively inexperienced people, i would like to see more of an "innocent until proven guilty" approach to amateurs. god forbid we do something differently from the past generation, use machines or techniques that haven't been applied to bike frames before. the thing that rubs me, with which i have a serious love/hate relationship, is the extreme conservative, even reactionary, nature to the creative critique in the industry. i love to see bad ideas crushed, but i hate that all new ideas are approached as bad. there are some people who don't hold to this model, and they often produce the work that is the furthest ahead of the industry. 

one thing in particular: praxis is heralded as the ultimate god of production. what i mean is that the heavy hitters come from mass production backgrounds, have hundreds and even thousands of frames under their belts, and demand that anyone else in their field also have such a repertoire. while certainly there is a lot to be said for the abilities of muscle memory, and the mental abilities to reproduce quality that accompany it, that lot has already been said. if that really is your god, if the best measure of a frame's quality is how many other frames have been made by the same producer, then the best frame builders in the world live in taiwan and china and are, to the consumer, completely anonymous. my point here is that, as long as your techniques are good, your frames will be good. as far as i can tell, here is what you need:

-a good design. there are many good designs out there to produce a variety of qualities, and you can alter and modify them infinitely to suit your own needs. modifying and generating designs does require a knowledge of how different bicycles ride and how different riders ride them.

-good production practices. as long as you are careful and meticulous in your work, any idiot can stick metal together such that it will not warp and will last effectively for ever. cut your miters accurately, clean and prep your materials, use good quality tubes and brazing/welding gear, and your bike will come out well. that is how the various bike schools (u.b.i., the doug fattic class, the nagasawa class, the former mike flannigan classes, the josh muir program) are able to produce frames that hold up even though they are built by people with no experience at all. while those bikes might not be timeless classics of engineering and design, they generally do work. hang some parts on there, put your ass in the saddle, hands on the bars, and feet on the pedals, and off you go.

alright, that is off my chest and i guess i feel better about it. having said that, i did spend today in the workshop playing with brazing and doing some plating in preparation for the completion of ben's stem. 

i prepped and brazed a bunch of scrap pieces together to practice my mitering, material preparation, brazing sequence, and brazing. once they were stuck together, i cut them apart to see how well the brass had penetrated the cracks and to look for pits, bubbles, or cracks. while i was brazing, i practiced forehand and backhand technique to try and get an idea of which would be more comfortable for me and see which lays flatter to make the finish work easier. here are some production pictures:

first, the miter. i am still doing these old school/ghetto way with a couple of files. the bits here are a bottom bracket shell that i had just fucked up on the lathe trying to turn it down into a sexy shape and a scrap of steerer tube which is the same outer diameter as a seat tube. so, good practice for doing a seat tube/bottom bracket subassembly. your miter has to be tight, matching the surface tube that it is mating to as closely as possible. that way, once you start to braze it and the heat starts to warp things weirdly, the curves will (with some luck/practice) pull into each other rather than twisting out of shape.

next, the tack. a small blob of molten brass to hold the miter in place before you heat it all up. the sequence of tacks is critical to the alignment of your component pieces: if you heat the wrong bits of the shorelines of the two tubes up first, the tubes will pull away from each other. here, i am doing a faux head tube/downtube junction. i started with the center of the obtuse angle as i was taught at u.b.i. this minimizes the migration of the long down tube. immediately after that tack holds, i moved around to the opposite side:

and there is the second tack, which hopefully counteracts whatever distortion occurred with the first tack. i didn't take pictures of the next two tacks, which i did on either side 90 degrees around the mitered tube from the first two tacks. the next step is very important for the strength and longevity of the joint. it is called tinning:

here is the first side tinned. it is the smallest possible braze, not even a fillet, just the brass that sucks into the seam of the miter as the joint reaches temperature. while it is initially tempting to skip tinning, it is a critical step in that it builds up an inner fillet. brass actually percolates through the junction of the two tubes and then sucks up the inside of the mitered tube as far as the heat effected zone goes:

there it is, a nice little internal fillet. i had some internal doubts about the necessity of tinning- after all, it is an extra step, and given that the whole joint reaches temperature during the braze anyway, wouldn't an internal fillet form regardless? the answer is no. in the joint pictured above, i went halfway around tinning, and halfway around not tinning. i cut the joint open at 90 degrees so that a quarter of the radius would be visible on each side. as you can see above, the internal fillet only reaches halfway around the inside of the tube. tin it to win it!

now, i realize that this is already a long post, but i also got around to messing with some brush plating techniques that i first learned about from my friend lance at square built bikes. lance gold plated the lugs on a particularly baller road frame using a brush plating kit. it was time intensive but did not require a huge initial investment in gear. getting small parts plated is tricky and very expensive, so a possible way to use my time instead of my (limited) money is worth exploring. i nickel plated some of the steering harness hardware on boson's cargo bike, but that was all a practical sort of plating, designed to prevent rust rather than to look good. for a stem, it has to be sexy. i did a quick polish on one of my brazes and plated it up:

not too bad at all! the tricky thing here is that it is almost impossible to tell where the chrome plating stops and where it will thus be vulnerable to rust. i will leave this scrap down in my basement where it is muggy and see where the rust forms over the next couple days. but for how little prep i put into the joint, it looks awesome. i am hopeful that this will be a great method for stems and maybe lugs. more soon, with any luck!