Originally Posted by mayukawa

I think those equations that you've listed are basically useless. I assume that you'll be designing the frame of the bike and not all the other components of the bike? Are you designing a race bike? I would assume so if you're trying to minimize weight as the primary goal. I think the engineers who design bikes have to design it for a theoretical rider of certain weight. Then they will have to design X amount of strength into the bike (depending on material used). Of course they will make that stronger than that minimum for safety margin. I think the hardest part about designing the bike isn't about plugging and chugging numbers into equations, but rather determining what kinds of forces (tension, compression, bending, torsion) the bike will experience and at what locations on the bike. After you know that, then you can derive equations. Yes, you'll most likely need to derive your own equations if you use non-round cross-sectional tubing. But even then, no equation will let you determine how to design a bike for a certain feel.