Ok, the geometry on the IRO's is driving me goofey. I'm looking at spending my tax refund on another bike and I believe a Mark V Pro is in my future. However I have no idea what size to buy. Traditionally, a 56 is too big for me. 54 / 55 seems spot on. Is the 53 going to be too small? I really don't like long top tubes and everyone says IRO's run small. I am 5'11 with a 31" inseam.

thanks in advance..

Ask the Man...honesty flows from him according to his customers

I normally ride a 49-51cm seat tube but after looking at the specs, the 50cm really has a 46cm seat tube c-c, so I was considering the 53cm size. But, I ride a 52cm top tube with 9cm stem on all my bikes so I went with the 50cm size since it has a 52cm top tube (and the $125 January special help the decision too).

It is a perfect fit. So simply put, you really need to know what top tube you ride.

Im the same hight as you with the same inseam. I ride a Jamie roy in a 56 and it fits well. I also ride a colnago in a 58 and a cannondale in a 60 so i guess I work well with bigger frames.

Milo