I was wondering about sizing (I'm am also about to get my first fixie). I am 5'8", 30" inseam and currently ride a Specialized 54cm road frame, but on the Specialized webpage, it says the seat tube lenghth c-t is 500mm with a standover height of 767mm. Does this mean that I should get the 50 cm Kilo frame? I just want to make sure that I understand the geometry correctly. Thanks!