Originally Posted by
terrymorse
Take your height in inches: 67"
Subtract 14: 53
Statistically speaking, that's the average ideal frame size in cm for your height, so I'd say you could fit fine on either a 52 or a 54. Unless you're a statistical outlier, which is doubtful.
The number 53 means nothing unless it's got more definition. In the old days it was more clear whether a frame was measured center to center or center to top. My 51cm LOOK is the same as a 53cm frame measured center to top. Trek uses the most oddball method of all brands, so their 54cm 6 series has the same head tube length and vertical size as some 51cm LOOK frames, like my KG 461. Both have the same 120mm head tube length. The size numbers are pretty worthless.