sjanzeir

I used to own two Dahons: a Mu D8 and a Speed D8. They had the same geometry, the same drivetrain, matching saddles and handlebars; they even had the exact same wheels and tires; the two bicycles were identical in every way - except for the frames. While the Mu was built around 6061 alloy, the speed was 4130 chromoly.

And yet, it is, perhaps, a testament to the quality of the engineering that went into each of them that while each bike had its own distinctive ride feel, the two weren't all that much different after all; the Mu tended to respond with a little more immediacy than the Speed, which tended to be slightly more deliberate in its reflexes (and noticeably, if no objectionably, heavier.)

With that being said, although I'm no engineer, I am more inclined to to chalk the difference up to the shaping of the frames than the actual metals they were made of. The Mu's arch-shaped main tube, with its boxier, more angular cross section, may have lent it a little more vertical and torsional stiffness than the Speed's straight, oval-sectiond main tube. And then there's the fact that the two bikes' folding hinges and locks are of completely different designs, which confuses things a little more.