Tech Back to the Future: Full 80's build

TCC

Tokyo Cycling Club
Jun 30, 2013
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#2
Oi oi!!!!

Now this, mate, is wicked.

Go as hardcore as you can on the details!

Well looking forward to seeing this thread develop.

Brilliant!!
 

TCC

Tokyo Cycling Club
Jun 30, 2013
2,362
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#3
Question (already)

Why is the BB unit threaded before welding? Welding will deform the shape of the shell, so the threads will need machining post-welding (this is how Odyssey does it...)

No criticism, just genuinely curious about the whole procedure and can't wait to see it unfold. :)
 

DeltaForce

Maximum Pace
Sep 17, 2011
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Toki, Gifu
#5
@TCC I was thinking the same. I had the same kind of question about the seat clamp. Notice it doesn't have a slot in the back. Apparently we will cut that after welding ,as it will deform like you said. We assembled the parts in the photo from what was lying around. It might change. I want to ask about it, but I suppose it might be possible to avoid drastic deforming with the expert brazing techniques that i dream I have.
 

George5

Maximum Pace
Oct 16, 2014
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#7
Thicker material of the BB won't deform as you are brazing with lower temps than TIG welding. The threads will be chased prior to assembly to clean them up.
 

George5

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Oct 16, 2014
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#8
Thanks George5, I'll take looks at that link. And by the way, the Delta brakes are surely going on this bike.
Hey I tried to race on them as well back in the days before Ergopower, They remind me of a hot looking girl but after a bit of a talk you realize she's an airhead. Surprised you are still in love.
 

TCC

Tokyo Cycling Club
Jun 30, 2013
2,362
1,291
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#9
Just get one of those underwater welding rigs, and do it in a swimming pool. Or something.

Odyssey have to machine their headtubes post-weld, as they use an internal headset system with the race a part of the frame. The welded part on the headtube is relatively far from the races, but they still deform, so I would be really interested to know how this is dealt with. Also, does cutting the threads into the BB unit before welding kind of mean you have to be an absolute God of jigs and welding to get it totally bang on straight? If you cut it after welding, you have more leeway with straightness.

This is all me just guessing stuff, so whatever, but yeah, interested to know!
 

DeltaForce

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Sep 17, 2011
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#10
Seems the threads will not deform enough that a thread tap won't sort them out after welding, thanks George5.

The head tube, along with the seat tube will be reamed after welding for sure.

Hey I tried to race on them as well back in the days before Ergopower, They remind me of a hot looking girl but after a bit of a talk you realize she's an airhead. Surprised you are still in love.
Yeah, I see what you are saying. But we always had so much fun when I rode her. I couldn't forget that when I was forced to sell the steel steed with C-Record, or the carbon bike with Dura-Ace. I usually raced on the Carbon bike, it just worked. But when I really thought about what I actually enjoyed riding, it was 'her', lol.
 

George5

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#13
Just get one of those underwater welding rigs, and do it in a swimming pool. Or something.

Odyssey have to machine their headtubes post-weld, as they use an internal headset system with the race a part of the frame. The welded part on the headtube is relatively far from the races, but they still deform, so I would be really interested to know how this is dealt with. Also, does cutting the threads into the BB unit before welding kind of mean you have to be an absolute God of jigs and welding to get it totally bang on straight? If you cut it after welding, you have more leeway with straightness.

This is all me just guessing stuff, so whatever, but yeah, interested to know!
again welding versus brazing. Things are brazed up with lugs, everything is lined up square of the BB, no need to worry about not being square. Minor differences are "set" on the table prior to final finishing.

is the tube lengths pre set for those parts, as angles would be different for different size bikes. Does that make sense.
The brazing material fills in the voids between tube and lug created by various angles so, no, tube sets aren't fixed. Extreme sizes it gets a little more involved. Check these pics out http://www.kirkframeworks.com/blog/2009/04/24/rare-opportunity/ and you'll see how the lugs are a guide for the tubes that are perfectly flush due to the mitering of the tubes. DK is a master builder and has some great ideas, his frame fit missive is well known in the industry. http://www.kirkframeworks.com/blog/2009/06/19/riding-tip-3/
and more good stuff
http://www.kirkframeworks.com/blog/2009/04/23/riding-tip-2/
http://www.kirkframeworks.com/blog/2009/04/03/riding-tip/

If you want to have a look at what's on offer http://www.cycle-frames.com/bicycle-frame-tubing/LUGS/ *Warning: can cause major loss of time and cash assets.
 
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DeltaForce

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Sep 17, 2011
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#15
Love this - Question - is the tube lengths pre set for those parts, as angles would be different for different size bikes. Does that make sense.
Asked Maeda san a similar question; whether the lugs were specific for different angles. Maeda san answered with something similar to @George5 for your question. A degree either way was possible with one lug.
 

DeltaForce

Maximum Pace
Sep 17, 2011
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#19
Awesome. Good luck.
I've been thinking about doing this too. What kind of torch do you have? Oxy-acetylene?
Don't have a tourch. I'll be using whatever I am loaned by Maeda san at his workshop. It looks a lot like the Oxy-acetylene gear I used in high school engineering classes back in the day. I'll have to do some practice, haven't done any brazing since then, lol.