Buying Time: Which Aero Equipment Offers the Most Benefits?

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No. 5: TT Frame and Fork

The biggest benefit of a TT bike is that the geometry fixes you into an efficient, aerodynamic position, which is difficult to achieve with a normal road bike.

These days TT bikes are available in a wide price range, and some of the affordable models offer the same benefits of the flagship version. According to Brownlie, a good time-trial bike can save up to 20 seconds over a 40-kilometer time trial over a normal road bike, based on the aerodynamics of the frame alone.

Don't Listen to This

John Cobb recommends using earplugs during a time trial. He's confident that you will ride faster using earplugs because the body associates the volume of the wind to the level of exertion. The earplugs might help you stay calm even when your legs are searing with pain.

Aerodynamic Savings

Aero Equipment

From (Original)

To (New)

Drag Difference (G)

Time Saved In 40km ITT (Seconds*)

Speed Suit

Road bib and jersey

Nike Swift suit (Not standard skinsuit)



Body Position and Aerobars

Upright, on bullhorns

Normal tuck on aerobars



Aero Helmet

Road helmet

Aero TT helmet



Body Position

Normal tuck

Tuned wind tunnel tuck



Front Wheel at 10-Degree Yaw

3-5 spoke

Deep rim 12 spoke



Shoe Covers

No shoe covers

Shoe covers



Rear Wheel at 0-Degree Yaw

Any full disc




Front Wheel at 0-Degree Yaw

24 spoke aluminum box-section rim wheel




New Aero Bike Frame

Standard tubing TT bike

Aero tubing TT bike



Aero Helmet

Decent aero helmet

Best aero helmet



* For a rider who rides 40km in 48 minutes (50 km/hr). Calculated using T=0.464 x D, (a simplified version of an equation formulated in 1999 by Chester Kyle, a pioneer in cycling aerodynamics since 1974), where T is the time savings in seconds and D is the drag difference in grams. Each savings in drag, expressed in grams from the above table, is multiplied by 0.464 to provide an estimate of the time savings, in seconds, over a 40km time trial. Sports aerodynamicist Len Brownlie, Ph.D. provided the data for this chart, which he has compiled over the past eight years during wind tunnel tests. Based out of Vancouver, British Columbia, Brownlie provides aerodynamic consulting for teams, individuals and manufacturers, including Nike's Project Swift. For more information visit