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Steel is real!
February 14, 2014 7:11 AM   Subscribe

A great thread detailing the building of an old-school steel bike frame.
posted by pepcorn (24 comments total) 22 users marked this as a favorite

 
I rode a 1963 internal hub 3-speed for about a decade. It was pretty ugly and heavy as sin, but it was pretty indestructible. A friend of mine who was an ex-bike shop person took me to Goodwill to look for a bike, and she convinced me that was the one. Then we took it a reclusive blind bicycle mechanic to have it fixed up, and, by the time he was done, that bike could plow through a car door without stopping. It was amazing, and I miss that bike.
posted by GenjiandProust at 7:30 AM on February 14


This is great—I've seen a ton of "framebuilders at work" pictures, but I've never seen the entire process from start to finish documented so well.

That seat cluster, oh man.
posted by enn at 7:36 AM on February 14


Beautiful!
posted by asperity at 7:42 AM on February 14


That's great stuff. I'm on BikeForums a lot, and like many forums there are too many rude and stupid comments. This thread is about the most polite one I've ever seen. Nice to see it can be done.

And the bike? Totally cool. I am also impressed with the rack. Perhaps easy compared to the frame but so delightfully cool. Love the design.

My favorite comment, clearly written in jest: "I'm not sure I understand... is this the mold, over which you will lay the carbon fiber? "

Anyway, thanks for this post.
posted by cccorlew at 7:44 AM on February 14 [1 favorite]


Check out this project bike from Waterford.
posted by rocketman at 7:55 AM on February 14 [2 favorites]


Bike Forums are a constantly shifting pantheon of newbs and nostalgic experts who remember when they were newbs. The year or so I was active as a newb, it was a helpful and positive place, unlike the MTBR forums. A year later, reverse that. It goes back and forth, depending on the voice of the most active and expressive posters at any given time.

This thread is from 2005, so during one of its civilized phases, I presume.
posted by Slap*Happy at 7:56 AM on February 14 [1 favorite]


If you are in Bozeman, you can visit Strong Racing Frames and maybe see a build in action.
posted by 445supermag at 8:04 AM on February 14 [1 favorite]


So I actually started doing this a few years ago and now I have a half-finished bike frame in my basement (life, etc.). These pictures are great, but like a lot of these kinds of photo spreads they really don't show just how much work is involved.

If you want to do this yourself in your basement (and it's totally possible, with a few caveats), you'll need a few things. The cheap route is to go with hand tools and wooden jigs - a hacksaw to cut tubes, files to shape ends, and lots of sandpaper.

You also need a torch. Lugged steel bike frames can be assembled with silver solder brazing which a process very similar to plumbing work. Silver solder melts at a relatively low temperature, so you can use a MAPP gas hand torch for the lug work. Unfortunately, silver solder flows using capillary action so wherever you require welds not involving a lug (such as the seat stay to seat tube joint shown in the link), you need brass. Brass brazing requires a higher temperature, so a real torch is probably necessary. I was able to at least assemble a fork using brass and a MAPP torch, but not having assemble the bike yet I have no idea how strong the welds are (and in fact I'm a little terrified it will just collapse as soon as I put weight on it).

Anyway, the part involving fire is really only about 2% of the effort you'll put in to building your bike. Most of the time spent involves filing and fit checking. Assuming you don't have to bend your lugs, I set up my tubes by first rough cutting to an approximate length and then marking the curvature with the lug - insert tube into lug, mark the line around the inside of the lug, and you have an outline of the material you need to remove. You can do the cut with a hole saw (either attached to an end mill or a power drill) and a jig, but I don't have those so here's where you start filing like crazy. First get the rough shape with the large files, then you get the needle files out and do the fine shaping, constantly fit checking against the tube it's going to join to. The lug is there really only to provide some extra strength; the real joint is between the two tubes, so they need to mate very precisely or the silver solder (remember, it flows via capillary action) won't get in there.

So the lugs have been prepped using roughly a linear mile of sandpaper, the tubes have all been cut and shaped (I think I logged 40-60 hours or thereabouts just filing tubes), so now it's time to braze the main triangle. You need a jig, since you want all the tubes to end up in the same plane and a crooked bicycle is hard to straighten out. Professional framebuilder jigs are on the order of thousands of dollars, so I make one out of thick, stiff particle board and scrap wood. The actual brazing process is quite like soldering electronics - a flux paste is applied to the joint, and then it's heated until red and the solder wire is fed in to the joint until it comes out the other end. You can solder a main triangle in under an hour.

For the next 20-40 hours, break out your finest metal brushes, needle files, and sandpaper because you've got to clean up all those joints and get rid of all the excess shit you just melted on to the frame. If you're good (and apparently I'm not), you'll use just enough solder to fill the joint and no more. If you're sloppy, you have gobs of silver solder seeping out of the joint plus a bunch of burned flux paste and this all has to go. Scrub heavily with the metal brushes to remove the flux, then go to town with the files and sandpaper on the joint edges.

Now that the main triangle is done, you can repeat this process for the rear triangle and the fork, each of which also need another jig. After that's done, you can prep and attach any greebles (brake bosses, cable hangers, etc.) in much the same way (only you're going to need to brass braze these, and you need more jigs).

There are only a couple steps that are hard or expensive to replicate in the basement shop. Bending fork blades is something I didn't try to do; I brought the parts to a local framebuilder and he did it for me. He made his own bending forms out of hard wood, but given the tools I had at my disposal I couldn't make something accurate enough. The other thing I haven't gotten to yet but will pay someone else to do is the chase-and-face - chase the threads in the bottom bracket, face it to the proper width, and also ream the headtube for the bearing cups. The tools required for those tasks are hundreds of dollars each, and for a one-off bike it's a bit of a stretch to justify buying them when the local bike shop will do it for me for 20 bucks or whatever.

School is ending soon so I'll be back to a normal 9-to-5 life this summer - maybe I can finally finish my frame, assuming rust hasn't destroyed it by now.
posted by backseatpilot at 8:06 AM on February 14 [13 favorites]


Yeah, I'm not especially active on BikeForums, but when I was in 2009 I remember it being a pretty civil and helpful place. I guess its visibility has a lot do with why the culture is so mercurial. Either way, this is a very satisfying set of photos.
posted by invitapriore at 8:52 AM on February 14


One of my dreams is to build my own bicycle. I figure at some point I'll just drop money and hit up something like Yamaguchi's frame building school. Until then, I have a 1999 Specialized Allez that I need to build up from last year.
posted by gucci mane at 9:03 AM on February 14


I think part of it is you are seeing an esoteric subforum that probably doesn't see the Pinkbike type crowd. Like on MTBR for example the general public forums are sometimes just ridiculous, while the regionals and most manufacturer ones are much better behaved.
posted by Big_B at 9:05 AM on February 14


Check out this project bike from Waterford.

Ahh, Waterford Precision Bicycles. Legendary history, because when Schwinn was sold, they spun off the factory in Waterford, WI. That factory made the Schwinn Paramount, the legendary top-line Schwinn, and really, they're still making the Paramount, but with 40 years of better materials technology behind it.

But there's a lot of hand labor involved, which is why the Paramounts always cost so much more than the lower tier Schwinn frames, using the electro-forge process. Those spit out very strong 1010 steel frames in minutes, and the entire process started with 1010 steel sheet. 1010 is by no means the lightest steel in the world, but it's tough, and with the EF process, what resulted were damn near bombproof frames.

Hower, the lugged Paramount and filet-brazed Sport Tourer, Super Sport and Superior frames took much longer and skilled labor to produce, and rather than stamping welding up 1010 sheet to make the tubes and fittings, they used seamless steel tubes and alloy fittings. The filet-brazed bikes used 4130 cro-moly steel, the Paramounts used Reynolds 435 and 531 steel, with double butted tubes, to get the weight down further.

If you can find one that fits, they are great frames -- all of them, but don't expect a lightweight EF frame. If you can afford it, the Waterfords, built like the paramounts but with the new air-hardening steels like Reynolds 735/835 are amazing frames, and since the labor difference between a stock brazed-up bike and a custom is almost nil, you can get a bike that actually fits.
posted by eriko at 9:12 AM on February 14 [2 favorites]


eriko: "1010 is by no means the lightest steel in the world, but it's tough, and with the EF process, what resulted were damn near bombproof frames."

Wait, compared to what? I always thought the benefit of 4130 over gas-pipe steel was that it offers better tensile strength per unit weight.
posted by invitapriore at 9:23 AM on February 14


I always thought the benefit of 4130 over gas-pipe steel was that it offers better tensile strength per unit weight.

Don't confuse AISI 1010 with gaspipe. Gaspipe is mild steel, less than .3% carbon. 1010 is a high carbon steel, 1% carbon, and it's hard to make good 1010, because even trace amounts of other elements can wreck havoc on the steel. Sulfur is the worst. Maganese is OK, but usually you only see some Mg in 1020 steel, but tempered 1020 steel is *very* hard and very brittle, it's basically tool steel.

Don't get me wrong -- 4130 is a better steel than 1010 for bikes, which is why Schwinn used it in the more expensive bikes. But don't deride well made carbon steels like 1010. Cromoly is stronger per gram than carbon, but carbon is vastly cheaper than chromium and mollybedammned, err, molybdenum, which is why you use it in situations that aren't weight critical. And, to be honest, for most bikes? The easiest place to knock a pound of weight off the bike is the rider. :-)

Mild steels, however, while being vastly cheaper than even carbon steels, are vastly worse for bikes. They're basically as dense as 1010, but vastly weaker. That's what your $100 store bike is made from. So, you either need massive tubing, or the thing just breaks or rusts out in a year.

Unlike the aluminum alloys, all are easy to weld up and machine. The ideal reasonable cost bike aluminum alloy is probably 2024, but you can't weld it with common methods. So, you instead see 6061, 7005 and at higher cost, 7075, all in the -T6 temper.
posted by eriko at 11:00 AM on February 14 [5 favorites]


1010 is usually considered mild steel. Carbon is about .1%, not 1%.

Mild steel is perfectly fine material for bike frames. Schwinn used mild steel for their old EF frames. The advantage of 4130 or other fancier steels is that you can use less of it (and thus lighter weight result) to get comparable durability (or the same amount to get superior durability). 4130 is also trickier to weld, if welding is the desired method of joining.
posted by 2N2222 at 12:03 PM on February 14


1010 is usually considered mild steel. Carbon is about .1%, not 1%.

Yeah, appears to be so
posted by RustyBrooks at 12:11 PM on February 14


If you want to nerd out about bike building specifically, the framebuilders list (now on Google Groups rather than phred.org) is full of interesting details, and characters.

Want pictures of builds, shops, and more? Oh boy: Joseph Ahearne, Mitch Pryor, Rick Hunter, Peter Weigle, Ira Ryan, Alex Wetmore, Tony Pereira.

Well, there goes the rest of my day.
posted by lantius at 12:24 PM on February 14


Carbon is about .1%, not 1%.

Wow, I screwed that up. Thanks, guys.

Still, 1010 is a decent steel. It's not gas pipe, even if I can't remember the damn specs.
posted by eriko at 1:06 PM on February 14


I found that project thread a while back, when I was playing around with the idea of building a motorcycle from scratch, which became building a moped from scratch, which became building a bicycle from scratch, which became buying a bicycle off craigslist and fitting it out as a moped, which has since resulted in a million components and a very pretty bicycle sitting in pieces in the screened porch and laundry room.

You guys seem like you know a whole lot about this stuff -- have any of you built/rebuilt a bicycle and then motorized it? Or do you think that would be a waste of a good bike?
posted by rue72 at 2:51 PM on February 14


I remember seeing that Bikeforums thread when it first was posted. It's cool to see some raw tubes and fittings built up by hand, with pretty simple tools.

This video is good, too: FROM STEEL: The Making of a Soulcraft, a frame maker with a lot of tools to speed up the processes. Many of those machine tools are older than he is. And a new precision frame jig to hold all the pieces in alignment.

I expected that the video might have been on metafilter before. Yes--here's the thread. Hey, it includes my link to this same Bikeforums thread! They are both worth posting again.
posted by jjj606 at 4:41 PM on February 14


You guys seem like you know a whole lot about this stuff -- have any of you built/rebuilt a bicycle and then motorized it? Or do you think that would be a waste of a good bike?

I'm not sure what your intentions are. But it's fairly simple and effective to convert bikes to electric bikes - with surprising speed/power/range.
posted by RustyBrooks at 7:45 PM on February 14


The amount of time and skill that goes into making a new bike frame makes me really appreciate the '70's and 80's used bikes I buy on Craigslist for $100 or so. Quality used steel bikes are a little pricier now than they were a few years back before the recent boom, but they are still downright steal.

I spend a lot of time on the Classic and Vintage subforum where everyone is polite and insanely knowledgeable. I hear the roadie and BMX forums can be quite nasty at times.
posted by jetsetsc at 9:32 AM on February 15


If you are in Bozeman, you can visit Strong Racing Frames and maybe see a build in action.
I have a Strong frame. I can highly recommend him, even though I did it long distance.

I spend a lot of time on the Classic and Vintage subforum where everyone is polite and insanely knowledgeable. I hear the roadie and BMX forums can be quite nasty at times.

Who’da thunk?
posted by bongo_x at 5:19 PM on February 15


Bring up Brit vs. French vs. Italian vs. Japanese standards, and then see how civil those fuckers are. Then let the bomb drop that Dutch is essentially Brit, and then stand way the hell back.
posted by Slap*Happy at 8:25 PM on February 15


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