Not Such A Catastrophic Newby Learning Experience (TM), News at 11

[veryredbike]

The weekend started off well enough:

table.jpg

Brazed another joint and minimal tweaking got my partial front triangle and printout matched up. I feel like my brazing is coming along nicely.

Then I got the paper out of the way and started in with the height gauge... and discovered 3/4 mm of twist over the length of the head tube. I figured that, by the time that reached the ground, it'd give me a few mm off from the handlebars, and got to twisting.

scrunch.jpg

The results were... less than satisfactory. Thinking I should have waited until I had a top tube to put that kind of torque on it, and should have listened to my gut when it said to ease off a bit. The twang it made was painful, but I learned, and I'm going to start over as soon as Henry James can ship me some stuff. Speaking of which, I'm going to go make a call...

[e-RICHIE]

...and discovered 3/4 mm of twist over the length of the head tube.

Three quarters of a mm OR three to four of them?
What method was used to measure this ^ atmo?

[NBC]

3 or 4mm of ht twist is huge over just it's length, i wouldn't have even started trying to twist it back !

are you using silver solder ? if so have a look at the set named oops atmo on e-richie's flickr account, and remove the down tube and use the frame as practice / for personal use only

only way to learn is by making mistakes, it's unfortunate that framebuilding gets expensive quick !

good luck

NBC

[veryredbike]

Richie: Somewhere between .75 and .85mm... measured by using a height gauge on each end of the head tube. Frame was clamped to the table on the drive side, seat tube was only about .1 off.

NBC: .75mm, silver... but honestly I think I'll start over on this frame. I know there's stuff I can do better, and I can always keep the joints around to try a repair later when I'm bored. Ain't that the truth!

[e-RICHIE]

Richie: Somewhere between .75 and .85mm... measured by using a height gauge on each end of the head tube. Frame was clamped to the table on the drive side, seat tube was only about .1 off.

You've made a big mistake 1) trying to fix it and, 2) caring about it. PS Measuring the O.D. makes no sense at all because the true center line is created when the reamer cuts the interior. And if you (or others) think the outer is mirrored by the inner, I have a bridge in Brooklyn to sell you. Get some precision cones and a rod that's at least twice-three times as long as the head tube, and use the center line as a guide.

[afwalker]

There really is some good brazing lessons to be learned from pulling a downtube or toptube from a lug. It will NOT be anywhere near as easy as you think. You will have to learn another level of patience waiting for the it all to come to temp. Consider just trying to pull one tube for practice, unless you already have done some. I bet it surprises you how darn good that joint was, just trying to get it apart.
cheers
andy walker

[veryredbike]

Richard: Roger, that all makes sense.

Get some precision cones and a rod that's at least twice-three times as long as the head tube, and use the center line as a guide.

Anyone have a good source on an assembly like this? No lathe in my toolkit yet.

Andy: I was mostly hesitant because I'm too frustrated for the re-assembly at the moment... destructive education on the other hand... yeah, I'll give that a go.

[druptight]

There really is some good brazing lessons to be learned from pulling a downtube or toptube from a lug. It will NOT be anywhere near as easy as you think. You will have to learn another level of patience waiting for the it all to come to temp. Consider just trying to pull one tube for practice, unless you already have done some. I bet it surprises you how darn good that joint was, just trying to get it apart.
cheers
andy walker

I've never done this with a DT or TT, but I had to remove CS once and I was SHOCKED how hard they are to fully warm up uniformly and fall out (positioned DO to the ground and hung something heavy from the DO while heating it up). Gave me a whole new respect for frame tube replacement/repair.

[veryredbike]

Maaaaaan, now I'll have to use this drum of it I bought to dispose of bodies instead.

Edit: maybe I should pick a show not about serial killers for my next Netflix/Amazon binge.