mildly on topic: using a pair of shimano 600 doubles for a junk bike. i put them on a 107 bb (i believe the original was 119, according to velobase); i'm just using what i have sitting around. the big problem is this: the non drive side crank arm is a whole lot closer to the chainstay than the drive side arm. to my knowledge, un57s are symmetrical, so what gives? anyone have a reason/solution?