@ misskaz: didn't mean to imply 650c was a junk solution. for a purpose built bike, it's appropriate. i was referring to people who have 700c frames and putting 650c wheels on it. this inevitably leads to them complaining about lowered bottom bracket height, incompatibilities with brakes, etc. also: you don't need to have a step through frame. there are new "WSD" bikes that use 650 wheels, compact frames with sloping top tubes, etc. look up georgena terry bicycles, specifically their older style frames with a 700c rear wheel and a 24" front wheel if you're looking for a horizontal top tube.