worth upgrade aksium to ksyrium?

is the ksyrium really worth its much higher price compare to the aksium? they basically look the same shape exept maybe the material (on the higher end ksyrium) and the hubs. aerodynamically they should perform the same? but just that the ksyrium is stronger/lighter?

in this test, the Aksiums tested 3 watts more aero than the top Ksyrium ES, and only a few watts 'slower' than many very expensive wheels. Only 5.2 watts less aero than $5000 (AUS) Lightweight Obermayers, which is about the same as using 2 latex tubes!

http://www.rouesartisanales.com/article-4934445.html (takes several seconds to load)



..............................."watts absorbed at 50kph"

Zipp 808....................................18.1
Ritchey WCS Carbon....................19.3
HED Hed 3..................................19.7
Vuelta Carbon Pro WR...................20.8
Easton Tempest II Carbon..............21.6
CKT Splendor...............................21.7
Mavic Cosmic Carbone SL...............21.9
Shimano WH-7801 Carbon 50..........22.9
Campagnolo Bora G3......................23.0
Rose Aerospoke............................23.0
Corima Turbospoke .......................23.1
Bntrga Race X Lite Crbn aero..........23.4
Fulcrum Racing Speed....................23.7
Gipiemme Carbon 5-5.....................24.1
Tune Olympic Gold 2005.................24.1
Shimano WH-7801 Carbon..............24.4
FRM FL-R 23 SD Aerolight...............24.6
Corima Aero.................................24.7
Lightweight Obermayer..................24.8
Xentis Mark 1..............................25.0
Citec 3000S Aero.........................25.5
Shimano WH-R560........................26.1
Lightweight Ventoux/Standard........27.3
Campagnolo Eurus........................27.8
Tune Skyline 2006........................28.1
FSA RD-600................................28.7
Mavic Aksium Race.......................30.0
Citec 3000S................................30.6
Ambrosio X-Carbo........................31.5
Campagnolo Hyperon....................32.1
Mavic Ksyrium ES.........................33.2

The data is for 50 kph (31 mph). It would be interesting to see what the data is for 30-35 kph, i.e. about 20 mph. I think that would be a very good point of comparison for non-racing enthusiasts - folks who like good gear but realistically only surpass 30 mph on the occasional down hill. 20 mph is a darn good cruising speed for most in that category.

For racers- what I've written is irrelevant because they not only go faster, but do benefit from small improvements.

Power from wind resistance is roughly proportional to velocity^3, in the absence of wind.

Dan

Like Dan said, power required to overcome aero drag is proportional to the cube of velocity. So, to "convert" the table to watts @ 30 kph (18.6 mph), the conversion factor would be the ratio 30/50 cubed (.6 x .6 x .6 )......which equals .216.

That means the power required @ 30 kph for the "worst" wheel on 531's list, the ES, would be just over 7 watts, while the "best" would use just under 4 watts.