Originally Posted by
grwoolf
I bought an aero bike (Madone) earlier this year and the difference is real, but not 1-2 mph real (unless you are starting at 30+mph). 1 mph at ~25mph translates to about 30 watts. I think my madone frame/bars is good for ~10-15 watts @25mph compared to the tarmac it replaced (same wheels). Trek claims ~20 watts savings, but I know I'm not getting that.
With a top aero frame and bars combined with deep aero wheels compared to box rims, you might be getting close to 1mph at 25mph. If you are in a better position on an aero frame, 2mph or more is absolutely possible, but that's not typically a frame limitation. That said, a 58 roubaix with a huge head tube compared to 56 venge or tarmac could facilitate a more aero fit).
Hi grwoolf,
Nice to hear from you and its been a while. Let's see if my old memory serves. Aren't you a tad over 6' and you either owned or still own a high end 56cm Roubaix at some point?
As usual, I find your comments spot on. The 1 to 2mph diff is comparing the VIAS Venge with deep section wheels to a larger and more upright Roubaix with box section wheels and not a Tarmac at similar size to the Venge.
As you know, on the pecking order, body position and then wheel section both vastly trump any aero cues when comparing framesets...especially between Tarmac with some incorporated aero design...say with same headtube length....only handful of watt diff at very high speed.
Agree with your comments. True A to B between Tarmac and Venge with same wheels, same size, riding position etc is probably only 10watts at 24-25mph if even that. I mean the world champ Sagan chooses his Tarmac over the VIAS for many outings and no pro wants to give away free speed. Then there is the weight difference as well...Tarmac can come in lighter than the VIAS.
Btw, as to flagship bikes, I believe you chose the mac daddy...the new Trek Madone is amazing.
Any pics of your Madone with or without your Tarmac for comparison?
Cheers.