Frame Building: Day 9 & 10

Well, internet statistics seem to indicate that these frame building posts are the least interesting. Even the spam bots are ignoring them. However, this is the last full day of class, the last day we’re going to have torches running, and the (exciting) conclusion to this story. So if you don’t mind I’ll press on and finish it.

Thursday: When things went wrong

As of Thursday, with only a day and a half left to work,  it seemed inconceivable that we’d have rideable bikes. True, the structural components were in place and aligned, but what about things like brakes, cable guides, and for godsake what about water bottles!? Most everyone had torches and drills running the whole day in order to finish before Friday.

Case of the Troublesome Bridge

I was a little ahead, but I still had lots to do. And a problem. The seat stay bridge that I measured and mitred late the day before was too low to accommodate a 650B wheel, even without fenders — although it would ride fine without a tire. I hadn’t taken into account the seat stay supports. I could leave out the supports, but it would look more like a production bike, and I didn’t want that. They were only 1.5mm thick, but there is one on either side and 3mm on a 7 degree angle changes the position in a not-so-insignificant way. On the plus side, the bridge was too long, not too short, and it’s easier to remove material than to add it. So back in the vertical mill it went. (I was advised it wasn’t a job for hand-mitring with so little time left as any mistake would result in even more time lost.) Luckily, the hole I drilled for the braze-on to mount the fender was dead center, so the mill didn’t have to be reset between shaving off the two sides. Dan, who helped me with it on Wednesday reran it for me and it fit perfectly.

As it turns out “perfect” is a relative term. It’s still too low to take fenders on a 650B rim with a 42mm tire. This is something I would have noticed if I a) was working at my own pace and b) had test fit the wheel I wanted to use. The fault was in my measurements, I hadn’t taken into consideration the bridge’s tube diameter, nor the height of the lip on the braze-on boss to which the fender is attached, which is an additional 2mm. It doesn’t sound like much, but 2mm here, 4mm there and suddenly the 14mm fender clearance I had budgeted was gone.

The chain stay bridge didn’t have this problem because its placement was by in large determined by the ovalized portion of the stay tubes. The bridge was much easier to mitre so to mate with the round portion of the stays rather than the oval portions.

Botched Bottle Bosses

After brazing the bridges, I realized there wasn’t time to clean up and bask in the glory of what I’d done. Nope. On to the next part. As soon as I shut off my torch, I spun around to the jig cabinet and grabbed the water bottle boss jig. I quickly placed the two dummy bottle cages thinking to myself, lower is better. I wondered why people didn’t really lower them, so I placed the seat tube bottle really low. The school has an angle drill that makes quick work of these holes. I cleaned up the holes with a deburring tool, file and emery cloth and brazed on four bosses. Boom!

What next? I looked into my baseball cap where I set aside all of the braze-ons I’d need for this bike, and grabbed the chain hanger. This one I didn’t use a jig, I just balanced it on the seat stay hoping that the flux wouldn’t cause it to float onto the ground. It worked but I wouldn’t do this again. Then I grabbed a cable guide jig and brazed three of those on, two on the underside of top tube for the rear brake, and one on the drive side chain stay for the rear derailleur.

Top tube cable guide ready to braze.
Chain stay rear derailleur cable guide ready to braze.

The Cantilever Controversy

Since the frame was in the stand still, I decided to braze the cantilever brake bosses next. This is where things start getting messy. A confluence of measuring mistakes caused these to be misplaced on the frame and eventually the fork. I’ll admit to some of those errors, but my biggest error was, again, not test fitting the placement with a wheel installed. I grabbed the brazing jig for this task and stuck those suckers on good and tight.

At this point, the frame had about four brazings worth of dried flux caked on it, slowly turning to glass. I decided that removal was something I could do the next day or at home and started to mount the braze-ons to the fork. The jig for this is probably the least useful in my opinion. It has registration marks for distance from the hub, but doesn’t take into consideration fork rake. My fork rake is extreme by common standards, roughly 68mm, which compounds the problem for this jig. It also has a problem applying uniform pressure to the left and right braze-ons at the same time. With the flux all up in there, it’s hard to see the gaps. This began my endeavour to learning to fillet braze with silver… pretty much a waste of time and silver.

Cantilever bosses being silver brazed to the fork.
Brazing the cantilever bosses silver to the fork. The jig measurements don’t account for the fork rake.

These mistake in the placement of these four crucial parts wouldn’t become apparent until I tried to build the bike four days later.

The shop was fuming hot this day and a little cross breeze from the open doors on either end was little relief. So I was actually glad to hop back on my bike and ride 100 minute commute back home. On that ride, I looked down at my bottom bracket as I often do. The front derailleur kept grabbing my attention for some reason. After a while, I realized it was located on this bike, right where I placed the water bottle bosses on my new frame. Doh! That’s why they don’t put them so low, I thought to myself.

Friday: Making Things Right, Sort of

I let Joseph know what I’d done with the bottle bosses and apparently the no-torch-rule-on-Friday is more of a guideline. I drilled a third hole above and inline with the other two and quickly brazed on another boss.

The rest of the day was spent removing most of the flux, facing the head tube, reaming the seat tube, adding threads to the steerer tube, and retapping and facing the bottom bracket. This was only a half-day, but by far the most physical. When we’d all finished, we had our pictures taken, spent some time asking questions about the business ends of frame building, and were given our certificates and a handshake.

Epilogue

On Saturday I tried to build the bike, well, just put the rims on and noticed the front canti bosses were too high. Then I noticed the rear ones were waaaay too high, above the rim and almost high enough to install Paul Racers. I pulled the rim off and spent a few hours removing every molecule of flux with metal tools and emery cloth. When the frame is just steel, silver and brass, it’s quite a beautiful thing, even if the brazing is done by an absolute beginner.

Cleaned frame. Notice the incorrect positions of the cantilever bosses both fore and aft.
Cleaned frame. Notice the incorrect positions of the cantilever bosses both fore and aft.

On Sunday, I shot an email to Joseph asking him if he’d move those bosses for me. In the end, we agreed on Tuesday afternoon and he was kind enough to do that for me for just the price of the silver. The next day I tried to paint it with some primer and the only color the local one-stop-shop had. It was a blue mess, literally. For the price of getting it powder coated by a professional, trying to hand paint it isn’t work the the time, expense and sticky mess to me. My brother dropped it off at his powder painter, Zollwerks in Dundee, OR on Thursday who turned it around in just a day. Fine work.

I got the frame back around 4 PM on Friday and had to catch a train the next morning at 6 AM. I literally threw the bike together, mostly, the rest in a suitcase and headed for Seattle. I’m waiting for the last parts to arrive today and will take it on a brief ride this evening and maybe get some beauty shots of it.

All in all, my experience at the United Bicycle Institute was extremely rewarding. I feel they give the dedicated student enough knowledge and experience to build bikes on their own, and enough resources to get help when they need it. I would do it again. And many students do take the class again. I find myself less interested in TIG or Ti classes now, but could see returning to the chromoly brazing class to concentrate on fillet brazing next time.

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Frame Building: Day 8

Day 8 was spent mostly truing the frame one last time, measuring the chainstays, creating the points, and brazing them to the frame. Once the seat stays are in, the frame “is what it is” Joseph told us — the frame’s alignment is pretty much locked in without having to resort to permanently fatiguing the steel.

Seat Stays

The finish work for the points (the parts connecting the seat stays to the seat  tube) was pretty amazing, a bit like jewelry making. I chose to add “spoons”, dished out points made from pieces of scrap tubing. I kept the points pretty shallow, about 2 cm. Longer would have been more elegant, but success would be more likely with shorter ones — and the pace of class was quickening.

First, the seat tubes are cut at an angle to create the length you want, then scrap tubing is rough cut to match the length of the angled opening. The stays are then mitred by hand and the scraps brazed on with brass.  (If the the spoons were brazed with silver, they’d just fall off when the stays were brazed to the seat tube.) After that cools, the rough edges of the spoons are snipped off and then comes a careful filing of the excess steel around the spoon. It has to match the radius of the seat stay so it appears to be a single piece of material. When finished, you can see the layer of brass sandwiched between the steel of the scrap and seat stays.

Seat stay point from the back showing the layer of brass holding the spoon and stay together
Seat stay point from the back showing the layer of brass holding the spoon and stay together

The tricky part is doing both sides exactly the same. Then they are brazed to the seat tube… in my case the lug.

Test fitting the seat stays.
Test fitting the seat stays.

Using a file, grooves are carved into the lug. This gives more contact area between the stays and lug for silver. It doesn’t take much silver to make an incredibly strong bond and it could be done so the silver can’t even be seen. However, I globbed it on anyway because I hadn’t convinced myself that that is actually true. Carbide radial saw blade teeth are brazed to a steel wheel and they don’t come off, so I should be a little more conservative with silver in the future.

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That took a good portion of the day, along with demos of how to use some of the many jigs for braze-ons. When the day was done, though, the frame was finally rideable.

A Visit to the Ahearne Shop

After a long, very hot, day in the shop we rode as a group to Joseph’s own shop to see a working shop. The learning environment of the school’s shop is intentionally sterile and perhaps overly equipped, so it was good to see another where not one, but two pro frame builders work. Joseph took us on a tour and demoed some of his own equipment. The most interesting two pieces to me were his torch, which was more like a scalpel compared to the “hammers” we have at the school, and his abrasive tube notcher. The latter, I came to learn, is used mostly for knife makers but can be made to make quick work of most tube mitring jobs if the right attachments are used. Joseph had some add-ons machined just for the purpose of making tube mitres, so what would take me 30 minutes with a file, he can do in maybe 30 seconds with some set-up time and finish filing. Pretty impressive stuff!

He also introduced us to Christopher Igleheart, or just “Igleheart”, who has been building frames… I think someone said for centuries. Joseph and Igleheart share their shop space, which seems to be a good idea for professional builders like them to reduce costs and have an extra pair of hands close by to help with tricky brazing jobs. Joseph used to share space with Mitch of MAP Bicycles before they lost their space to some sort of eminent domain and Mitch moved to Chico. However, the two haven’t lost touch and we got to see, and even purchase, a new handlebar they created together, which is a slightly longer version of another upright bar they created. I really like Mitch’s handiwork and got to see one of his frames up close.

We also got to see a lot of other bikes Joseph has made over the years and hear the stories behind them, including a motorized bike and his second fillet brazed frame. One bike in particular was nearly finished and being fitted with a top-shelf Campy group. No expense was spared for this bike going to the buyer in Chicago. (Joseph promised pictures of that bike will be appearing on the Ahearne Flickr in weeks to come.)

I bought an Ahearne t-shirt from him and some other bling before heading off on my 20 commute back home.

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Frame Building: Day 7

To be clear, a lot of what I write during this class is basically notes for my future reference.

I had my first measurement mishap today. Luckily it was only in the drawing rather than the frame. I’d drawn in the tire centered over the diameter of the tire rather than the radius. This threw off the position of the chain stay dimples. But like I said, it was only in the drawing. The actual position of the dimples were marked with the actual wheel mounted to the free hanging chain stays.

Although I noticed the problem, I didn’t figure out the cause. Joseph did, and that allowed me to continue with brazing them in place. It went, meh, okay. The fit was rather rough at the bottom bracket. The ports are straight but the chain stays are tapered, so every time I inserted the tubes, the points on the bracket points would spread apart again. Long story short, it caused some large gaps that needed to be pinched while hot (a good two-person job) and a truck load of silver to fill. Next time I’ll take more off the drop out end so the bracket end will be less into the tapered section when I trim.

Most of us also had time to align the stays. I must’ve had some good karma because it was nearly perfect. The drive side dropout was a millimeter low and the bracket spacing was 127 mm instead of 130 mm. Both were quickly fixed.

Next was the seat stays, which have been cut, test fitted, and I’ve prepared the points. I’ll be using a traditional points, spooned, and they’re ready to braze when I get in tomorrow. A lot of today was demos so I didn’t have the time to finish them. Also a contributing factor was I wanted a long scallop here, so that meant more time to file and book-match them.

I wasn’t able to use my first choice of seat stays because the end diameter of the .7 mm tubes was too small to fit the plug-in style rear drop outs. That would mean I’d have to cut off a good portion of the small end of these tapered tubes, and that would make them too short to reach the seat tube lug. So I’m using .8 mm. It’ll have a stiff rear triangle. Jan Heine seems to prefer this design but I have not enough personal experience for an opinion.

Regardless, the entire bike is now .8 walled tubes, butted to .5 on the main triangle, except for the seat tube, which is .9/.6 as that is the only diameter we had available.

Besides the seat stays tomorrow, we start adding the brake posts and bridges. As a special bonus, we’ll have the honor of visiting Joseph’s own shop after class. I’m looking forward to that. Not so great is that Ron, the owner and UBI’s chief engineer is heading back to Ashland tonight for the remainder. I’m going to missing his encyclopedic knowledge and technical input. On the bright side, maybe the biggest need for that is gone as there isn’t any more structural work to be done and the jigs have been put away.

Here’s where it stands:

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My little corner of the shop. In the vice is the partially completed frame with a Grand Bois Hetre EL on a Velocity A23 rim I made a few months ago. This is the actual tire and wheel I intend to use, which is helpful to have on hand when designing and measuring the frame.

Did I mention it was hot? Today was the hottest day of the year, I believe. Like most shops I’ve been in, it gets hot inside, especially when working. I thoroughly enjoyed the ride home though, despite the heat.

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Frame Building: Day 5 & 6

On Friday, I left with the head tube and top tube brazed together. By the end of the day Monday, the whole front triangle was brazed and the chain stays ready form mitering. I needed to drill a vent in the seat tube under the lug. Like most things, front and back orientation is important but easy to reverse.

By the end of today the chain stays will be brazed on, the frame aligned, and I’ll begin on the seat stays, which take the longest.

Here’s where we stand:

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Frame Building: Day 4

For those of us fillet brazing most of the day was spent practicing that technique. The lug people began working on the forks in earnest. As a group we went through the process of drawing the rear of the bike to scale in order to select and optionally bend chain stays.

I was able to finish the fork, let it cool and get it into the heat tank before class was over. I’m excited to see the results without flux all over it.

The 20 mile commute is getting easier but I’ve noticed what I’m calling “competitive commuters”, so far only men. More on that later. Time for class.

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Frame Building: Day 2 & 3

By the end of Day 2 we’d completed mitering tubes, silver brazing lugs, and copper brazing dropouts. For theory we talked about bike design and geometries, and fitting. It’s the only day we’re given homework, which was to calculate some frame dimensions based on the bike we’re building. Our instructor, Joseph Ahearne, and I are the only two building 650b wheeled bikes, although his is for touring. One fellow is building a purely road bike, another a mountain bike, and another guy is building sort of a roadish cross bike. After test riding Joseph’s personal bike, very posh I’ll add, I’m convinced that a shorter top tube might be the best fit for me.

Ron, the owner and chief engineer, gave me some ideas that caused me rethink the order I’ve been designing frames. Adjusting my process caused me to come up with angles that are closer to available lug angles and tube measurements that come out nice and round. Some of this is beginner’s luck, I’m convinced because the order I’m still using is still different than the one he described (which is bottom bracket drop, seat tube angle and length, top tube, head tube angle, and then down tube.

Day 3: Today we continued practice brazing but also drafted full-size paper drawings of our frames, measured them and had them verified. We also began working on our forks. Mine has a 68 mm rake, which is at the limit of the bender, within 2 mm. I’ve chosen the Pacenti Paris-Brest fork crown for its capacity to accept wide tires, and Henry James insert fork dropouts, mostly because I’m feeling more comfortable with my silver brazing skill than my brass. I feel like I should have the fork completed by the end of the day 4.

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Freshly bent fork blades. The dropouts I’m using are beside them (the careful reader will notice they’re both non-drive side). All of that is sitting atop the full-scale diagram of the frame.

More photos are forthcoming. I’m having trouble accessing them from my phone at the moment.

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Frame Building: Day One

I’m writing this from a coffee shop, people are dresses in either cycling garb or semi-retro hipster attire, two middle age women are making out on the sofa, my barista is talking describing her favorite form of contraception (male contraception), and I am sipping what is arguably the best mocha I’ve ever had.

Yes, it can only be Portland.

Monday was packed, leaving the house by 6 am to make to the school by 7:45, then all day in class until 5, and then home by 6:30. Although the 100 minute commute is beautiful one, I’m not used to it and it’s wearing on me. I figure that will go away, but it doesn’t leave much time in the day for much else. Working from home spoils a person.

So far we’ve gone over the equipment learned to get the torches going and tune the flames well. We’ve brazed a couple of water bottle bosses, mitered a top tube, filed lugs, and brazed them. That’s just the first day. We haven’t started working on our actual bikes yet but by Friday we should have our forks done, that is for the people that aren’t fillet brazing.

We’re at lunch now. Photos and more to come later when I have time at a computer.

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Making Good in My S&S Investment

Last night I put the Soma Grand Randonneur into the S&S case, in preparation for my flight to Portland.

To pack an S&S traveler coupler equipped bike, one much remove the following items: rack, fenders and bottle cases obviously, but also the drive side crank, seat with stem, and handlebars with stem.

Once done, the bike splits in two and fits into the case quickly, perhaps five minutes. There aren’t a lot of ways it fits, somewhere around 1, but how many ways do you need?

I threw in quite a few other parts for the new bike, but as you can probably tell from the photo, there isn’t room for the rack and fenders. Those are stowaway in my suitcase.

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If you read the current Bicycle Quarterly, you might be of the opinion this is a pointless exercise. In The article is about Japanese “rinko bukuro” travel bikes They make unsupported claims about couplers on a bike’s performance. The essay continues with a series of photos where Natsuko demonstrates how she readies her bike for travel. (I’m on a plane and writing from memory, so I might have the names wrong.)

It all seems elegant, refined, as if an ancient Japanese tradition, not unlike a tea ceromony. Couplers are for Neanderthals.

I take issue with a couple of things.

First, I have noticed no appreciable differences in the way the bikes rides or perform with couplers, either of them. If this were true, and negative, I wouldn’t have installed them on my Soma.

Secondly, Natsuko’s bike appears to be maybe a 49 cm frame size. A smaller frame is obviously going to fit into a sack much easier than the 61 cm frame size I ride.

Lastly, this method of packing is only valid for carry-on, and only on trains, and only in Japan. Heavy qualifications. As an American island dweller who must fly and required to relinquish his bike to TSA, none of those apply to me.

While I’d rather all forms of mass transit had internal bike racks like Amtrak, that’s not the world we live in. Most of the world doesn’t live in Natsuko’s world either.

For the rest of us, we have S&S couplers and bike shippers. For my efforts, I saved $100 in airline fees. Two and a half more round-trips with this bike and they’ll have paid for themselves.

Update: Explaining why TSA didn’t shut the lid is another topic.

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And also this….

By way of BSNYC, there is this, proving:

  • Some solutions don’t need problems (they come with their own)
  • There’s a niche market for cyclists who have had an assectomy
  • Bike design is easy — anyone can do it
  • You can get a patent for just about anything

Where to start? Well… it’s orange. How weird is that?!

Some thoughts: There should be a law against abusing an old Schwinn like that. Where does one get a brake cable that long? From the photos, it looks like ‘riding’ this bike results in quite a lot of pain. Note that this seatless bike still requires a seat tube… I would have moved the front mech to the down tube.  Yeah, that would make this all better.

As the pictures hint, apparently you can’t reach the pedals with your feet slung behind you. WHO WOULD HAVE THOUGHT?!  That’s probably why this guy just left the pedals off:

And so did this guy, and why he added a engine:

Of the three designs here, this the only one where laying your bike down won’t snap your head off.

 

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