I have two questions:
1) how can i change the lengthof the "down tube" of a standard bike frame ?
I can only change the "Seat tube length" or "top tube length"
2) how is it possible to create my own bike frame, not using your standard "diamond frame" ?
i cannot find this function, is that not possibel ?
Many thanks for your clarification,
If you lengthen the top tube, you will inevitably lengthen the down tube as well. Although you cannot directly enter a length for the down tube, there are several ways to change its length. Some of the ways are described at: bikecad.ca/toptube_frontcenter. Another approach would be to increase or decrease the head angle.
BikeCAD is primarily intended for designing diamond frame bikes. Having said that, you can develop less conventional designs by turning off the top tube or down tube or using multiple seat stays, or attaching the seat stays at unconventional locations. Curving the tubes can also result in more unusual designs.