R4 Aero: World’s Fastest Tire

The R4 Aero—or what we refer to as the world's fastest tire—is just that. We set out to create a tire that excelled in aerodynamics and in rolling resistance. The result, the fastest tire on the market, in every wind angle, at every speed.

What does this mean for you? The R4 Aero lets you use less energy to ride faster, shaving time off your ride compared to the next best in class tire:

  • more than 9 seconds in a 10k time trial
  • 37 seconds in a 40k time trial
  • more than 3 minutes during an Ironman cycling leg

Technical details

Total drag force

Finding the World's Fastest Tire was a matter of locating a tire with low rolling resistance that didn't suffer from aerodynamic drag and an aero tire that didn't feel sluggish. This Total Drag Force, measured at wind angles of 0 to 10 degrees, is a combination of both aerodynamic and rolling resistance drag. Like all of our tires, we put this tire up against the competition and it did not disappoint.

Total Drag Force

Comparison of Aerodynamic Profiles

Aerodynamic profile

Using CFD (computational fluid dynamics) Bontrager designed a 22c elongated tire profile that more closely matches the profile of today’s rims and slices through the wind at every angle.

Aero wings

Tubular tires do not cover the whole rim surface creating a small indentation where the tire meets the rim. Clincher tires fit inside the hook bead of the rim allowing the rim to create a lip next to the side of the tire. These lips and indentations disturb the air and that turbulence leads to aerodynamic drag. The R4 Aero tires include a unique aero wing structure that improves airflow over the tire-rim interface.

Comparison of Aerodynamic Profiles

World's fastest wheel system

Our fastest wheels just got faster! Wind tunnel results prove that adding the R4 Aero tire, the World's Fastest Tire, to our proven Aeolus D3 wheels provides the fastest wheel system in the world. What does this mean for you? The combination of the Aeolus 9 D3 wheel and the R4 Aero tire allow you to use less energy to ride faster.

Comparison of Aerodynamic Profiles

Combining the R4 Aero tire with any depth Aeolus D3 wheel provides a drag savings of 10 grams and higher. That’s free speed just by swapping tires.

Comparison of Aerodynamic Profiles

Product details