Archive for March, 2014

23
Mar
14

Third Time’s The Charm

You could’t tell it from my increasingly-infrequent posts, but I am building another bike frame. My third. They say that the “third time’s the charm” – which implies that your first two tries left something to be desired. Maybe. And, yes, I do seem to have gotten the hang of the basics of the frame building thing this time around. This bike is going to be “nicer” and the first two noble efforts. Better tubing, better geometry. Fewer screw ups.

So while I still ain’t Irio Tommasini, Tom Kellogg or Darren Crisp, if you want to throw a leg over a genuine Taylor frameset you’r gonna have to see me.

Rather than do a repeat of the “Eight Tubes” series that I did while building Number 2, I’m just gonna mark my progress by posting some pictures from time to time.

Number 3: The Details

Tubing: Columbus SL
Lugs: Cinelli (copies by Long Shin)
Measurements: Top Tube 55cm (c-c)
Seat Tube 55cm (c-c)
Head tube 140mm
Chainstays 41 cm
Angles: Head tube 74 deg.
Seat tube 74 deg.

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Proof that this is a low buck operation is the “jig” that I used to braze the main triangle of the frame. The “jig” consists of some leftover 1in square tubing that I had from the Fork-A-Lizer. The beauty of 1 inch square tubing is that (1) it is cheap, and (2) it is usually fairly true, with no twists. Because is it square, I figured that I could use it to align the head tube and the seat tube in place while I brazed the frame.

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Put the fork on the frame, and it starts to look like something.

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Ahh…Chainstays. The tricky part about chainstays is getting it all lined up – making sure that the stays are parallel to each other and the dropouts aligned so that, when you are all done, the wheel sits plumb on the bike. For the first two frames I just clamped the chainstays in the vise, lined up the chainstays by eye, squared up the drop outs, took a deep breath, and then had at it. Both frames turned out fine…perfect actually….but that was just dumb luck. So I built al little jig that does a much better job of aligning the chainstay tubes. I assembled things, and then checked the alignment for twist, etc., before I fired up the torch. The result: ‘effing perfect. And repeatable.

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FInally, I’ve been collecting parts for the final build. Like its sisters, Number 3 is going to be another “old school” bike, which appeals to me. What I have so far..

A cool “drillium” Sugino Super Mity crankset

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New-in-Box Shimano 600 front and rear derailleurs

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I should be done in early spring….stay tuned.




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