a guy I ride with ( Victor - Started and ended M2racer with his son ) and he rides his 10.72 lb bike every group ride we have. I believe he's in his 60's and climbs like a goat. just unbelievable. But he would also say his bike is more of a conversation piece than anything else.
His folding bike weighs in at just about 14.0 lbs. pretty phenom when you see it. but I can squeeze his top tube with 2 fingers and it feels like I am going to crush it. not a race bike by any means.