Time Trial Frame Design
Aerodynamics aren't everything. You still have to be able pedal and keep the bike on the course.
Spin Arts triathlon / time trial frames are built with a primary goal of putting you in the most aerodynamic position from you can generate the greatest power. Your trunk length, flexibility, pelvic structure, total leg length, relative length between upper and lower legs, and arm length all have a bearing on where you sit over the pedals and where the wheels end up under you. I optimize my bike frames to your body.
In addition, we've all watched professional riders miss corners like they have never ridden a bike before. The time trial position is not the most optimal for bike control, so I build time trial frames with slightly more steering stability than road bikes.