This is a very similar topic that I've raised before. I'm on a budget and need to buy a used endurance road bike. Will probably have my local LBS to a fitting after getting the bike. I've taken all the measurements, did the Bike Fit calculations and another system on a different website and have talked to many cyclists. At 6'1, logically I should probably go with a 58 but calculations show I should be on a 56, possibly because of longer than normal femur and upper body ratio less than my lower body. Inseam is 34.25.
If I guess wrong, should I go low or high?