Ebike frame metal

[arik5233]

Hello everyone,
I need to know about the strength of metal sheets for my e bike frame.
I'm working on building my e bike from scratch and have already completed the design process and now I'm facing problem choosing the sheet metal. Among steel, stainless steel and aluminium which one would be rigid enough to hold off 3+ KW power and what should be the minimum thickness of the sheet?
The sheet will be folded and welded.
So
1. Which metal sheet? And
2. Minimum thickness of the sheet?
Thank you

[Retrorockit]

Generally speaking steel and Aluminum have about the same strength per pound (this varies with the alloys though) The Aluminum will be thicker for the same weight so may be prefered due to that.
The thing is bicycle frame tubing is highly evolved. With tapering wall thickess available (butted) hardened and special alloys available including Titanium. It can be hard to beat..
A lot depends on your design. A wide span may be strong in one direction, but flexible in another, and need to be thicker due to that. 3KW is about 4HP. Probably a 45MPH vehicle.
Material selection should be known early in the design process. It's not an afterthought. I can't make any specific recommendation, except err on the side of caution, and go heavy.

[arik5233]

Can I dm you?

[Retrorockit]

If you want to. I'm a retired mechanic and hotrodder. Not an engineer. So I know how things work. I also know "what I don't know". That can be very inportant sometimes.