Narrower Road Bike Tires Outperform Wider Options in Speed Test, Study Shows

According to a recent experiment conducted by cycling journalist Trevor Raab, narrower road bike tires—specifically 700×25 mm models—demonstrated superior speed compared to wider 700×32 mm tires under controlled conditions, challenging common assumptions about tire width and performance.

How Was the Test Conducted?

Raab tested four Schwalbe Pro One tire sizes (25 mm, 28 mm, 30 mm, and 32 mm) on a closed 1-mile loop near the Trexlertown Velodrome. Using Favero Assioma Pro RS-2 power meter pedals, he maintained a consistent 275 watts (4.2 watts per kilogram) over three laps for each tire. The tires were mounted on Reserve 57|64 wheels, which have internal widths of 25.6 mm (front) and 24.5 mm (rear), optimized for 29 mm tires.

Tire pressures were calibrated using Silca’s Tire Pressure Calculator, and actual widths were measured with digital calipers. The 700×25 mm tires measured 28 mm, while the 700×32 mm tires reached 33.2 mm at the front and 32.8 mm at the rear.

What Were the Results?

The 700×25 mm tires completed 3 miles 17 seconds faster than the 700×32 mm tires, averaging 24 mph versus 23.3 mph. The 28 mm and 30 mm tires followed the trend, being 11 and 15 seconds slower, respectively. Raab attributed the speed difference to the test surface (smooth pavement) and aerodynamic factors, noting that narrower tires reduced frontal area.

Why Did Narrower Tires Win?

Three factors influenced the results, Raab explained. First, the fresh pavement minimized rolling resistance advantages typically associated with wider tires. Second, the test speed of 23 mph meant aerodynamic drag dominated, favoring the narrower profile. Third, the Reserve wheels were optimized for 29 mm tires, aligning with the 25 mm tires’ measured width.

“This isn’t a universal rule,” Raab cautioned. “Results could vary on rougher surfaces or with different wheelsets.”

What Does This Mean for Cyclists?

While narrower tires may offer speed benefits on smooth roads, wider tires provide advantages in real-world conditions. They offer better puncture resistance, grip, and comfort on uneven surfaces, as noted by cycling journalist Tara Seplavy in a separate analysis. Raab emphasized that the “fastest tire depends on your riding environment, wheelset, and personal priorities.”

Cyclists are advised to conduct their own tests, using consistent power outputs and controlled conditions, to determine the optimal tire size for their setup.

Key Takeaways

• Narrower tires (25 mm) outperformed wider options (32 mm) in a controlled speed test on smooth pavement.
• Aerodynamic drag and wheel design significantly impacted results.
• Wider tires may still be preferable for rougher roads, stability, and puncture resistance.
• Testing with personal equipment is crucial to determine the best tire size.

For further insights, readers can explore Schwalbe’s tire specifications or Bicycling magazine’s in-depth coverage of cycling equipment. As Raab concluded, “Speed isn’t the only metric that matters—balance performance with practicality based on your riding needs.”