The only thing that makes the IRO anything like a track bike in it's Geometry, is the high bottom bracket height-which you want if you're running a fixed gear. The ST/HT angle of my Mark V =73deg/74deg which is in fact more laid back then my roadbike which has a 73.5 ST angle. Contrast this with a Pista which has a 75.5 ST/74.5 HT angle-that's seems more tracklike to me-really steep angles. FYI - My Mark V is probably the most comfortable road bike I've owned. Just did 130mi on an IRO on Sunday - no aches/pains anywhere aside from leg fatigue. Also when you're sizing one for yourself look at the the C-C measurements, not the size name. i.e. a size 59 IRO is actually only 55 C-C, as it's measured to the top of the seatclamp.