Fillet brazed steel bikes, handcrafted in Oklahoma.

Cleo’s 29er 2

I got a bit more work done, so here’s another post. This being my first bilaminate frame, I’m just realizing how much work this is. I’ve got all the lug sleeves cut

and this is the one I brazed on in the last post. It’s got all the flux off, and it’s mitered. This cut very nicely on my lathe with the homebrew tube clamp.

I also got the seat tube sleeve done

Then I went on to cutting the seat tube to fit the bb shell.

The holesaw is mounted on an arbor from Paragon Machine Works, purveyor of fine framebuilding supplies and tools. The one modification I made was to drill a 1/8″ hole in the center of the arbor for a piece of weld rod to slide into. That’s the thing sticking out, and I use it to point to where the center of the radius to be cut will end up. I take it out once the tube is lined up.

The flash seems to stop that thing cold, but it’s spinning.

See?

Then I checked it for square, cleaned it up with a file and tacked it to the bb shell.

because having your seat tube in the center of your bb is a good thing

I put a tack in the front and back, then tinned the whole joint just a bit before putting a small fillet around the front. The tacks hold it in place, and let you adjust it a little to insure that it’s square.

Then I ‘tin’ the whole joint, meaning I heat it up and run just enough brass around to coat the whole joint but not build up. That will hold it in place really good, but there isn’t enough brass to pull it out of alignment as it cools (and the brass shrinks). The small fillet around the front is because the down tube will cover that spot, and I don’t want to leave it bare, but I don’t want to trim the end of the down tube to clear the fillet. I want it to go right up to the corner where the seat tube meets the bb. (Gospel from the book of Garro)

I’m still getting used to this new flux, it looks burned every time. It’s not, but it looks like it. Anyway, that’s in the sink. I think I’ll go downstairs and take it out when I’m done with this post. These things always feel just a little bit like talking about fight club. But, inquiring minds want to know.

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