I'm 6'1" and have a 34" cycling inseam and am comfortable on a 60 cm CAAD7. I believe the geometry is the same as the CAAD8. I was between the 58 and the 60. They do make a 59 but only as a special order frame only. The fitter told me that if I was gooing to race, the 58 would be more responsive but have a greater saddle to bar drop and ride a little stiffer. If I was going to do fast group rides and centuries, the 60 would be smoother and more comfortable as long as I could adjust the reach to fit. I have put 6000 miles on the bike and 8 centuries with no complaints. I am glad I went with the 60 cm for the type of riding I do.