I too have been wondering about average speed on my new 'bent versus my averages for the same routes riding DF bikes. So far I only have four real rides in to measure my 'bent average versus previous DF averages. They both seem to be about the same, although I will say I have a greater perceived feeling of speed on the 'bent when I lean into turns. I think the lower vantage point (Bacchetta Giro 20), makes it seem faster even though it would appear to be about the same speed. I was able to ride home with a tailwind last night and maintain higher average speeds during some areas than I think I would have on a DF bike. Also, going in that morning, there was a pretty stiff headwind and I didn't feel at all as if I was gaining any advantage on the 'bent. However, I'm willing to bet that if I had a DF bike to swap over to at that same time, I could've ridden the same sections and probably felt a 25% increase in effort needed to get the DF bike through the headwinds versus the Giro. Of course I'm still developing 'bent legs as well and so I bet that affects efficiency as well. I'm willing to bet that as I become accustomed to the ride, adjusting my cadence (it doesn't seem as easy to maintain higher cadences on the 'bent), I'll start to realize the speed increase everyone talks about, especially on the flats, and those headwind days.