Frame Building?

[Bob]

So, with all this happy welding action going on around Bikerowave...
Is there a plan on trying a hand at frame building?

Anybody know anything about brazing?
Ultra Couture Fancy Frames?
That would be pretty cool.

[Recumbent Dave]

Bicycle frame building has a reputation as being an arcane art; something that's practiced by wizened old Jedi masters, or else carried out by huge, complicated robots in Taiwan, attended by a small army of engineers, technicians, and metallurgists. This isn't so. Frame building is a craft like any other, with simple, consistent rules that mere mortals can master fairly easily, given sufficient attention to detail and care.

I've been a cycling nut since age four. I've assembled a few bikes from individual components, laced a couple of dozen wheels, and figured that building my own frame was the next logical challenge. I've built a few now, and thought I'd share my experiences, as there wasn't a raft of information available when I started my research.

Fair warning: I write here about my experiences building my first few frames. Not everything I say here is necessarily correct; indeed the only thing I'm sure of is that I have made and will continue to make mistakes.


Sizing is very important. No bike will work well if it doesn't fit you well. I've had a number of different bikes over the years - some too big, one too small, and the more recent ones pretty much right. I had a good idea of what the top tube and seat tube dimensions should be, so only had to work everything else out before I had a design that was buildable. My advice to anyone wanting to build a first frame would be to measure what you already have carefully, and put some thought into what you'd change if you had the chance. Could you do with more length, or a faster (steeper) steering geometry? Or longer chain stays, so you don't touch them with your heels?

I wanted to do a silver soldered lugged steel frame. I bike the look of lugs (except when they're overly ornate) and think it's a practical, strong way to build a frame. Also, I've never used a MIG or TIG welder before, so thought I'd stick to oxy-acetylene.

My criteria were:

High bottom bracket. Many road bikes use a 265mm bottom bracket height. As I wanted to use this on a track, I went for a bottom bracket 285mm from the ground.
55cm square frame. That means 55cm long top tube, and 55cm tall seat tube. I don't grock sloping top tubes, so made mine parallel to the ground.
Fairly steep seat and head tube angles. I went for 74 degrees parallel. Many track bikes go as steep at 76 degrees in the head tube, but I wanted to be able to use this on the road as well, so compromised.
Really short chain stays. I want a bike that sprints well; a thoroughbred. The length of my chain stays was dictated by wanting a 23mm tyre to just touch the seat tube when inserted all the way into the horizontal fork-ends.
An interesting point when designing a track frame is that the head tube ends up fairly long for a given frame size, due to the high bottom bracket.

Ok i'm going to go lay down meds are kicking in and I'l post more later

[Alex Thompson]

I don't grock sloping top tubes, so made mine parallel to the ground.

Grok.

Spelling correction ZING!!

[Art]

I agree with Recumbant Dave...

Zen masters n' shit. 

Especially brazing... There's also the 'tempering' afterward, so your 'triple-butted' tubes will retain all their tensile strength and not 'buckle' near a lug... 

Direct butt-welded joints are MUCH easier to perform, especially in steel, but you gotta remember that frames get made in a 'production-line' wherein you've got a series of the best people, who've practiced and honed their particular individual task in the line, doing one small portion of the building of the bike.

This is true from the designing of the geometry all the way down to the finish threading.

BUT...

I've seen some guys putting together carbon-fiber frames, sorta 'casually' over the course of several months, in their garages, a few hours here and there, and coming out with some a m a z i n g framez...

...then again the sheer number of mind-numbing hours and tweaky, finicky jig-work that ALL needs to be done before you even start making the 'yarn' tensioners, and setting up a 'gluing' zone so the rest of your whole life doesn't become 'epoxy & itches'...   

... which brings me to ultimately having agree with Alex, too...

"Gronk"  ... or was it "Zork?"

Faahhgeddabouditt...   

Unless you're into that sorta thing...   

[wilkie366]

Hi,

This topic interested me because I'm interested in building a custom classic style lugged steel road frame. Henry James seems to be selling a good kit..the question is does BRW have a welding gig set up now, and would somebody be able to help me learn brazing on some cheap tubes/ discarded frames?

thanks!
Bob

[Steve Mattson]

Why not take the lugged frame building course at UBI (United Bicycle Institute)?

[Morgan]

no, brw does not have a welding jig.  they's mad ducats, yo.

[gamecat]

That depends on what you mean by 'welding jig.' Or, I suppose, what you mean by 'mad ducats.'

http://toolmonger.com/2008/03/27/cheap-ass-tools-helping-hands-welding-jig/

[JB]

This is what is meant by a bicycle frame building jig.

http://www.henryjames.com/equip.html

Mad ducats apparently means $2500+

[gamecat]

Yeah, I thought I might have been missing something.

These things do look pretty awesome.

[JB]

You might dig these articles then:http://richardsachs.com/rsachsarticles.html

Richard Sachs is pretty much the man when it comes to modern lugged steel frames, although Sacha White's stuff is pretty kick-ass as well - http://vanillabicycles.com/frames/

[McTait]

This guy is a pretty open builder:

http://bikesbyzank.blogspot.com/

Blogs the process of making various sweet things.
His jig seems relatively lo tec.

[ScottS]

This is what is meant by a bicycle frame building jig.

http://www.henryjames.com/equip.html

Mad ducats apparently means $2500+

The best.

http://www.anvilbikes.com/gallery/categories.php?cat_id=15

Only $7200.

-ss

[ScottS]

FYI- Tomorrow at the San Diego Custom Bicycle Show, Brian Baylis (built frames for Masi California) will be teaching a seminar "Introduction to becoming a Framebuilder" at 1pm.

http://www.sandiegocustombicycleshow.com/

Seminars are included with paid admission to the show.

-ss

[Art]

Thanks so much Scott.. 

..again, you ROCK !!