> That said recumbents might be the most aero dynamic bikes, but lying down pedalling is less biomechanically efficient.

Even when you have something to push against?

Yeah. Lying down your glute is not activated as much. The upright position also gives better activation of the upper body which gives much better breathing.

Thanks!

I guess whatever the guys who are setting the human-powered vehicle speed world records are doing is probably close to the optimal trade-off.

Well if you go really really fast aero is the most important. The aerodynamics of an upright rider is worse than a semi truck. Also the breathing aspect is only really relevant for longer efforts. If you want to race 150 other guys through small European roads for 21 days in a row, up right is better.

Recumbent vs. upright is actually an over 100 year old battle, over misunderstanding each others needs and wants from a bike. Many recumbent people are still sour over UCI banning non-double diamond frames.

Thanks for all the explannations!

> Well if you go really really fast aero is the most important.

Yes, and in the context of the submitted article, aerodynamics is the only difference between riding alone vs in a peloton, isn't it?

Ha, now I wonder whether you could get better endurance performance, if you took the vehicle from https://www.engineering.com/story/human-powered-vehicle-brea... and stuck tank of pure oxygen in the chassis to hook the rider up to.