Originally Posted by
fuzz2050
An aluminium crank is usually pretty darn thick, and it would take a really skilled welder on a powerful machine to get enough penetration to safely weld on it. I'm not skilled, but I have a bit of experience, and anything above 1/4 inch makes me a bit nervous about weld quality. Cranks are usually much thicker.
Google up Marschall framework, they have a set of cranks they make out to 220mm i think, check them out.