Originally Posted by CIVEbike
About the aero frames vs not so aero..
I think the time trial bikes are designed that way because the 'aero position' is really only effective in speeds above about 25 mph. On a TDF climbing leg, you're probably not doing that a lot of the time so it becomes less important. Then the weight becomes more of an issue as well as things breaking. However, on a TT you may be doing 30-35 the majority of the race.
**I think**
This is not quite right. Most windtunnel testing suggests that anytime you are going above 14 mph you should be in your aero position because the decreased wind resistance is significant. Plus, your average ironman pro is more in the 22.5mph-25mph range and I guarantee the aero position helps them a bit.
Though you are correct that they are designed for the aero position and that the aero position has it time and place, mostly triathlons and TTs.
30-35??? sounds a bit fast for any distance to me.