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I highly doubt it's (ultra) light weight credentials. You could make it lighter simply by using Aluminum for the frame and rims instead- Though that^^ material should last a lifetime where Aluminum's crystalline structure doesn't lend itself to long term usage. What you're looking at is obsessive, expensive, compulsive and single minded. Depending on the quality of the welding chambers used it has a great strength to weight ratio but most of all it is bloody rare. No rust/paintjob worries is a bonus.

it like the difference between a consumer product and an industrial product. This is industrial of course.