Thread: frame welding
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Old 07-01-2015, 02:40 AM
graydog8josh graydog8josh is offline
Motorized Bicycle Elite Member
Join Date: Nov 2012
Location: Starkville,MS
Posts: 447
Default frame welding

Has anyone built a frame themselves? Im wanting to rebuild one out of real structural steel tubing instead of rigid conduit and I'm wondering if anyone has any ideas or tips.

I read that people making frames are using 4130 chromoly, and im wanting to go about the same size as the rigid conduit thinner.

the specs on rigid conduit
1/2 rigid
ID: .634
wall thickness: .110

so im thinking ill get some 4130 chromoly .875 OD, .058 Wall which will be half the thickness

I read people are building downhill bikes iwth .49 wall chromoly but im kinda scared to go too thin on my first chromoly frame, as i dont know how the metal will behave. ..

I do know that the galvanized rigid conduit is such a pain in the... to preclean and reclean and ventilate my shop space and it turns the shielded area around my welds a funny purple color if i get too close to it and that zinc coating turns fluffy and white and contaminates my welds and they end up looking junky.

I just have been using rigid because its really thick and and i got about 50ft of it for free. I wanted to open up my top tube so it would straddle my motor so i wouldnt have to worry about frame clearance issues and now i am opening my mind to doing real structural welding on my bike so i can go real fast w/o anything breaking.

I taught myself to tig weld for this so i really hope someone can give me some good tips and not just naysay. Im going to do it anyway i just what to see whats out there as far as information

So what do you think?
.49 wall or .58 or thicker?
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