Originally Posted by
berner
It seems to me that the most important measurement is the effective length of the top tube. If the bike turns out to be a bit too big it will never be completely comfortable. On the other hand, if a bit on the small side. a longer stem with the usual front to back adjustment of a saddle can produce a very good fit. Consequently I would go with the smaller size. As a rough guide, we are the same heigth and and the top tube on my bike is 54 cm but 52 or 53 cm would be a better fit for me.
Hey berner, thanks for the advice!
Yeah, my LBS gave me a similar suggestion with regards to the benefits of erring on the smaller size. Interestingly, the Orca Aero frame's Effective Top Tube length is about one frame size larger than you would expect:
SIZE / ETT
51 / 534 mm
53 / 547 mm
So maybe the 51 is the better fit? The 51 comes with a standard 100 mm stem, and the 53 with a 110 mm, so I was thinking on ordering the 51 with a 110 stem.