I note in a manual somewhere there is a claim that the frame is made of chrome moly on carby bikes. I am not sure this is true on any carby or IE. Can anyone confirm? I thought they were all cheap mild steel?
I don't think they are chrome moly but, having replaced a frame due to cracks, I can confirm they are pretty light, so probably not the cheapest mild steel either.
I reckon my carbed 97 SS frame is mild steel..........there was a sharp end of tube under the seat when I got it which cut my hand twice when cleaning under the seat (the bike was filthy under there) so I filed it nice and smooth.......it definitely behaved like mild steel, anyway.
I knew I had seen this before: Courtesy of 'The Motorcyclist' website..... According to technical types at the home office, the alloy in question is also known as Fe E 420 or E420M UNI 10296-1. ALS is common shorthand for alloy steel, and 450 is the factory's designation for this particularly complicated alloy. More corrosion-resistant than the familiar 4130 chrome moly (a.k.a. chromoly) variety, it's relatively easy to weld and has what engineers like to call "a high modulus of elasticity," making it more durable in a tip-over. ALS 450 debuted in the '95 916's steel-trellis skeleton, and is also employed on the Desmosedici RR, using a different diameter to maintain rigidity without increasing wall thickness. The 15.8-lb. Desmo-sedici RR frame uses four different tubes ranging from 18 to 28mm in diameter, with a wall-thickness of 1.5 to 2mm.
Bicycles too. For bicycles, they use double and triple butted tubes, which are thicker at the ends than in the middle. If it was as thin at the ends as in the middle, it would be a real problem to weld.
I have read an alarming post by a guy on the Ducati ms forum where he poured water out of his early SS frame after stripping the bike. Assuming the water will have been there for years and the early bikes seem to be mild steel, that is alarming surely? You would not really know what was going on inside. You can repair and powder coat all day long but the innards will be rotting through.
I replaced the frame on my SS and had no such problem. As I said, the frame was surprisingly light, so I doubt it was any old mild steel. That was a '96 model.
The welds on my carby SS look mild steel smooth and on my IE have those alloyesque creases in the welds.
I read they were chromoly somewhere aswell,it will look much the same as mild steel,but chromoly is seamless and they both weld pretty much the same.
Welds look very different on my IE. Could just be the welder but I suspect a different grade of metal
Can't say Zi Can't say I know much about welding but the implication here seems to be that one would weld chromoly with special chromoly welding rod. Is that really the case ??
Both the frames are mig welded,they will be done by a robotic welding machine now that will be the diffrance to look at rather than materials.
That you would use different welding rod for chromoly than for other more mundane steel. I guess you wouldn't want galvanic corrosion between the two though.
