Properly sizing a frameset online (Ritchey Road Logic)? Longtime lurker, first-time poster. My frame is cracked and I have mostly decent parts so I am thinking about just buying a frameset and paying the LBS to move stuff over. A friend suggested I look into steel frames since I want a metal frame and don't race a ton, climb hills and long distance. After Googling I am now enamored with the Ritchey Road Logic frame. But the closest dealer is 200+ miles away. So now my challenge is to buy this frame online in the right size.
Height: 6-6'1&quot;
Inseam: ~31.5&quot;, 800 mm
Current bike stack/reach: roughly 570 mm, 400 mm; not provided by the manufacturer).
According to the Ritchey guide that would put me at roughly a 55 cm frame (stack/reach 567/395). The next size down (53 cm) is 549/391, and the size up (57 cm) is 587/401. Current non-Ritchey bike is a 53 cm.
The head tube and seat tube angles mostly match up with my current bike, less than ~1 degree difference. The standover height (797) is 20 mm higher on the Ritchey but that's probably because my bike has a sloped top tube. But the 53 cm is closer to my current bike.
So two questions:

What else can I compare between the measurements to make sure 55 cm is more or less in the ballpark of what I need? Should I aim for smaller?
What's easier frame-wise to make adjustments with as far as stem length/angle/saddle position? Sizing up or down?

Many thanks.
I happen to be the exact same size, so I'll answer. I have a custom built road bike with 55cm c-t height and 57cm top tube. I'm using a 120mm horizontal stem and classic drop bars that have more reach than so-called ergo shape at the drops. If I for some reason wanted to have a stem with rise and ergo bars, I'd need even longer and lower frame. The 55cm Ritchey is a bit shorter and has a bit taller head tube but isn't that far off.
So, if you absolutely have to buy Ritchey, 55cm is probably the correct one unless know that your current frame fits perfectly and you want to change as little as possible.