You don't really say much at all about the "front center" in your description, or state anything about a preference for short or long centers, wanna clarify?
Grant 51cm McLean Toronto.Ca 58.9 is my magic front center number, formula or not...
Brian Baylis wrote:
I begin with the seat angle. Once I have established that I determine the top tube length/stem length combination. The actual frame size can vary a lot more than most people are willing to accept from my experience. Frame size has to do partially with position on the bike relative to several other factors in the design. As a custom builder, I don't just build racing style bikes. Bikes for different purposes can be different sizes for the same rider, but I find most people are too rigid in their belief of what "frame size" they take. The rest of the frame design isn't related to the ride as much, but have to do with weight distribution, fit, steering qualities, how the bike handles the gearing, etc., etc.. It's not rocket science really, but knowledge and common sense are very important. Otherwise you have to rely on formulas and whatnot. (There's that word again, what the hell is "whatnot" anyway?) I determine each of these dimentions based on the conditions the bike will face, the components, and whatever special needs the rider requires.
The resulting small frame designed this way is comfortable, steers beautifully, and rides and fits the rider the way it should (end of snip)