BikeTechReview.com

Zipp 1080: Deep wheel.  Slow tires?

How the tire you choose can mean more aerodynamically than the wheel you have, or are considering purchasing

Significance

Stage six of the 2009 Tour of California in Solvang saw Levi Leipheimer snag victory from David Zabriskie by a scant 8 seconds during the violent 30 minute effort.  During this time trial stage, Leipheimer chose the time-proven three spoke for his front wheel, while Zabriskie chose the new offering from Zipp: the 1080.  Did Zabriskie’s wheel choice lose him the stage victory?  Or, was it his front tire choice that may have cost him the top spot on the podium?

Rough CFD Simulation

by: BTR Forum Member: zebragonzo

This model is intended to show the flow of air around a rider and to give armchair aerodynamicists a chance to better understand how air flows.

Because of the complexity of the model and the limited time available to run it, the mesh has had to be simplified such that the accuracy isn't spot on. Additionally, the legs and wheels are not rotating. Finally, there are some areas that did not mesh quite correctly (front of the chainring, some of the rear wheel, top of the down tube). Despite these errors the simulation reports a drag of 2480g for both the rider and bike which is as would be expected for a cyclist in this position thus indicating that the error isn't sufficiently high that the model does not resemble real life.