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Which is more aerodynamic 4 spoke or deep dish(6 posts)

Which is more aerodynamic 4 spoke or deep dishPODIUMBOUNDdotCA
Feb 2, 2003 10:15 PM
I'm looking at getting a new front aero wheel. Anyone have any info comparing a Corima 4 spoke (or similar wheel 3-5 spoke carbon) to a deep dish low aero-spoke wheel like the Corima aerowheels or Zipp's.

Thanks,
Nick
PodiumBound.ca
some dated but useful info...Akirasho
Feb 2, 2003 10:41 PM
http://www.bicyclesports.com/technical/aerodynamics/watts_drag.html

... and some not so dated...

http://www.analyticcycling.com/Topics.html#Wheels Topics (follow the links)
http://www.analyticcycling.com/WheelsConcept_Disc.html#Coefficeints%20of%20Wheel%20Drag

Be the bike.
Infro from analytic cycling and then why use a tri/quad spoke?PODIUMBOUNDdotCA
Feb 3, 2003 6:23 AM
Thanks Akirasho.

Conventional 36-spoke
0.0491
Campagnolo Shamal 16-spoke
0.0377
HED CX 24-spoke
0.0379
Specialized tri-spoke
0.0379
FIR tri-spoke
0.0382
HED disk (lenticular)
0.0361
ZIPP 950 disk (flat sided)
0.0364

Leaves out the HED 3 spoke in favour of the Specialized tri-spoke though. But they are nearly identical in design. So if restance is more with a 3-4 spoke why do we use them? Its obvious why we use a disc.

Nick
Podiumbound.ca
re: Which is more aerodynamic 4 spoke or deep dishrogue_CT1
Feb 2, 2003 11:27 PM
The Hed 3, tri-spoke carbon wheel with 51 mm profile rim, is the fastest front wheel. Period. The most important factor in determining how aerodynamic a wheel will be is the deepness of the rim. You'll find that most carbon tri-spoke wheels have a deep rim. They are usually based upon the Specialized Tri-spoke wheels which later became the Hed 3. For the rear wheel only a disc is faster than the Tri-spoke wheel. Why else would our beloved tech-geek Lance use this very set up on his TT bike?
re: HEDcyclopathic
Feb 3, 2003 6:49 AM
Nimble claims lower drag numbers on CROSSWIND then HED-3 (which btw has slightly higher drag then original Specialized). Here's the link http://www.nimble.net/technology.html

This is not that mfg lie about their wheels, problem is it's all how you look at it. It is easy to design wheel to perform in head on wind; add yaw/change wind speed and results will be quite different.
more surface area= more aerostr8dum1
Feb 3, 2003 7:25 AM
but that all depends on the yaw of the wind. double disc is the most aero. increase the angle of yaw and the wheel with the most surface area is the most aero. wheel designers have to make compromises b/c more surface is less stable. thats why you can only use double disc on indoor tracks. the drag #'s on those sites are for straight on wind. On the track is the swirling with you as you go around. No. So just becuase one wheel maybe more aero at straight on wind (more a function of wheel width!!!), does not mean it will be the most aero wheel.

he hed maybe more aero than the corima at all yaws bc it maye have more surface area.