[simonsmithies]

This is true - the ergonomics as well as the aerodynamics are a step up. I would like to note though a disadvantage in ergonomics when it comes to hills, which nicely illustrates another feature - often unacknowledged - of conventional frames. I live on a hill and commute on a conventional/non-recumbent bike. There used to be a bearded white middle-aged guy living half way up our hill with a recumbent and I noticed the recumbent seemed way /less/ efficient on our hill climb. A secondary design feature for conventional bike geometry is how well it works on a hill when you stand up. There’s something about how you can use your weight, pulling on the handle bars at the same time as rocking the bike frame side to side, to maximise downforce on the pedals, that just works incredibly well for propelling yourself and the bike up a hill. None of that is available on the recumbent designs I’ve seen, and because the hill slows everything down, they get less aerodynamic advantage too. So while they’re great on the flat, I think a key limiting factor for recumbents may be that they’re not so good in hilly places.

[seadan83]

Ran into a fellow touring once with a recumbent and a trailer for his dog! All told, a 250lbs rig, few would be able to celebrate as much getting to the top of santiam pass in oregon (approx 4000 ft climb)!