Just reading the Cervelo claim on the new S5. It may be more slippery, but I find the drag reduction a bit hard to believe. 9.9 watts or 92 grams of drag: really? Do you know how much harder you have to train to get that kind of power increase? It also equates to a big change in position; if you modify your TT position to lose 100g of drag, you will be going a lot faster and have a pretty decent adjustment to make. Compare that to the claims of savings when compared to an already aero S3 frame with a narrow profile. Like some other aero claims, it just seems "too good to be true".
I know that when I did a TT recently, and a teammate of mine compared power with me (he has a better position, same model bike); we found out that our power is about the same, but he regularly puts 20 seconds into me in the weekly 7-mile TT. Recently, he had his 50mm deep Ritchey front wheel, and I had a Stinger 7, which is 140g of drag less at a yaw of 12.5 degrees. Comparing power, we were still within 2 watts of each other, but my "140g of drag savings" didn't change the fact that he beat me by the usual 20 seconds (140g of savings should translate into 16s of time savings). It doesn't directly correlate to the S5 claim, but just shows me that those claims should be taken with a grain of salt. I don't doubt that my Stinger 7 is faster than his wheel, but a few seconds at best.
I know that when I did a TT recently, and a teammate of mine compared power with me (he has a better position, same model bike); we found out that our power is about the same, but he regularly puts 20 seconds into me in the weekly 7-mile TT. Recently, he had his 50mm deep Ritchey front wheel, and I had a Stinger 7, which is 140g of drag less at a yaw of 12.5 degrees. Comparing power, we were still within 2 watts of each other, but my "140g of drag savings" didn't change the fact that he beat me by the usual 20 seconds (140g of savings should translate into 16s of time savings). It doesn't directly correlate to the S5 claim, but just shows me that those claims should be taken with a grain of salt. I don't doubt that my Stinger 7 is faster than his wheel, but a few seconds at best.
