I live in Styria, Austria
My passion is bicycles - especially handmade bicycles. After building two bicycle frames myself, I stuck with virtual frame building: rattleCAD.
rattleCAD 4.0 supports your bespoke bicycle frame design and build process with a fully parametric bicycle model and is fully written in Tcl/Tk.
In this design process, rattleCAD 4.0 guides you through several steps
rattleCAD 4.0 - rattleCAD 4.3.32 - Screenshot