Myths in cycling: wider tires are slower

There was no doubt that the narrowest tires are slower than slightly wider ones. Then we tested wider tires, and realized that the performance of tires doesn't change at all as they get wider. Based on this and other testing, we developed our Rene Herse tires and optimized them for performance and comfort on real roads. If you run wider tires at lower pressures, you increase the flex of the tire, but you reduce the suspension losses: the two effects cancel each other, and your speed remains the same. What about the aerodynamics of wider tires? Many riders believe that wider tires will be slower, because they have more wind resistance. We tested our tires on smooth pavement at 29.5 km/h, and found no speed difference between narrow and wide tires. If you ride much faster, then it's possible that wider tires have a little more wind resistance, but the difference will be so small that it'll get lost in all the other factors that influence your bike's speed.