Aerodynamic Properties of the Bikes/Wheels

[armstrong]

Hi folks

Just curious - I know that different rider/bike combinations will result in custom fits/designs for each professional rider, but why is there not a standard spoke design among wheels?

Comparing these two bikes from Astana used in the TT, (image here)
http://www.cyclingnews.com/reviews/photos/tour-tech-custom-bikes-for-almost-everyone/78748

The bike at the front uses a carbon tri-spoke design, whereas the bike in the back uses traditional spokes. I can't see how spoke design aerodynamics is specific between riders.

This might be a noob question, but why isn't there a consensus on wheel design?

 

[The Falcon]

because its not all about aerodynamics. Weight, stiffness, braking surface, rider preference, rider weight and power are all considerations in wheel selection.

There is no one correct answer.

 

[karlboss]

Conditions, courses, preference, a fair bit goes into the choice, the more standard the course, ie straight flat out and back no wind the more you'll see the same wheel being used. Once you throw in variables then compromises are made. High wind...lower depth, hills...lighter weight, corners ie acceleration...light weight high stiffness.

Then a big one...sponsors. Maybe everyone would love a Hed 3 (arbitrary choice) for the TT but if you aren't sponsored by Hed...

 

[Animal]

Tri-spokes are hell in crosswinds.

Well, wheels which have large surface area are hell in crosswinds. So that includes disks (obviously) and deep section spoked wheels to an extent.

 

[egtalbot]

To follow up on what animal said, trispoke wheels have some interesting handling properties. On the front, they are generally bad in crosswinds, and my experience has been that screaming downhill at 45-50mph a front trispoke is bad in almost any wind condition. Not all riders would agree with me on that.

On the other hand, I swear by my rear trispoke in any conditions. It's a little slower than a disk, but I can only remember one time that I got worried about its handling - downhill at 47mph in a crosswind.

Different riders have different experiences on this. Your bike setup makes a difference as well - more aggressive positions have different handling challenges than less aggressive positions, as do different aerobars.