Originally Posted by CliffordK

However, I disagree about mass production.

I think a person could cut batches of 100 tubes.
Bend a bunch of rear triangle tubes.
Build a rear triangle jig.
Weld up a bunch of rear triangles.
Same with welding up a bunch of main frames (perhaps in batches of half a dozen of each size).

Then weld the fork, main frame, and rear triangle independently, even at different times.

Smaller jigs may even make welding of certain components easier.
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