Just a geuss, but unless you have a very long torso, a male 6'3" would usually ride about a 60-61cm. I am 6'2", and usually take a 58-60cm frame, with a 58.5c-t-c top tube. That's just a reference I use when comparing to others of similar height. Also, the fact that you are a pretty big guy at 230lbs, your core muscles will take time to develope as well. This may be a combination of both proper sizing, and muscle strength.
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