If you’re not convinced about a Time Trial bike and going all out aero then consider the current world hour records. 49.7km on a Road bike, 56.375km on a Time Trial bike. It’s all down to aerodynamics, not extra power. The rider accounts for upwards of 70 percent of the drag in the bike-plus-rider equation. The power you need to overcome aerodynamic drag on a bike is related to your drag coefficient (determined by shape and surface), frontal area, air density and speed. You want to lower your drag coefficient and frontal area while making sure you can still ride your bike.