Are Wider Tires More Rapid? Comparing 26mm and 30mm Road Tires

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Tire width is the most important in road cycling. Usually, cyclists on the road mostly use tight tires (23 mm) or used smaller ones. Usually, these tires are quite light, and therefore they work fast. Now the choice of people has become quite different. Manufacturers are telling bicyclists to use wide tires (28 mm or larger). Now between the claims that they offer the standard of low rolling resistance and a more comfortable ride.

But which tire is the width of cycling on the road? And "are the wide tires sharp?", Now in two sizes, the Pirelli P-Zero Race TLR tire made two tests: 700 × 26mm and 700 × 30mm. These tires' width was chosen to correspond to a typical, narrow road motorcycle tire width and to reflect the perception of the tire by other road users.

Indoor Testing

The first test took place inside the house on the rollers, while the second was on a course in different road conditions. Indoor testing should give you reliable data to know any difference in rolling resistance between tight and wide tires. Still, in real-world conditions, estimating some positive and negative aspects of tires is also important. It is the place where the second test is performed. Most of us drive our bikes on the road in the real world.

In what we have experienced, when we talk about the width of the road-driven motorcycle tire, the balance between comfort, rolling resistance and aerodynamics is maintained. For instance, bigger tires may be more comfortable but may slightly reduce aerodynamic efficiency when used. Your road bike and riding style will determine where the balance is for you, but we'll suggest how to pick the right tire width for your needs.

Indoor Roller Testing

All these things in the game, including air and traffic, can be difficult. However, riding inside the house on the rollers in a more controlled environment can keep us separate. The width of the tire, namely, we want to test.

Indoor Roller Testing Frist PartTire Width

Easy to test. Take two sets of tires of different widths and ride at a fixed speed for a fixed time. Then we record the power needed to maintain this pace.

All these things, such as a motorcycle, wheelset, tire type, and riding position, will be the same in each race as the tire will be pressure, 26mm and 30mm, while both tires are flown to 90psi / 6.2 bar. If the width of one tire is faster than the other, what will need less power output to maintain the target?

The target speed was 40 km per hour, and the interval was 5 minutes. It would be best to assume that this test is not like a ride in the real world because the rollers' level is smoother than any road. The tires on the roller compared to the roads are quite different, as the small diameter increases the tire malfunction.

Indoor Roller Testing Second Part

Tire Width and Tire Pressure

In the actual world, we normally wouldn't use bigger tires with the same pressure as a narrower tire. As a result, the larger tire has higher casing tension, which makes it stiffer and less pleasant than the narrower tire. As you can expect, a 30mm tire that is 90 psi (6.2 bar) inflated is rather stiff. Wider tires are meant to be comfier, which is one of its perks, but in practice, we won't experience that advantage if the pressure is too high.

Higher tire pressures and casing tensions lower rolling resistance on perfectly smooth surfaces like rollers (or, in fact, a velodrome) because less energy is wasted on casing flex, and the contact patch is smaller. Wider tires need to be filled to lower pressures than narrower tires because we want the casing to flex and absorb flaws in the road surface in the real world, where roads aren't as smooth as rollers. The bike will bounce over these flaws if the tires are overinflated, which reduces grip and speed.

These were the pressures we tested at for this portion of the test since, according to Pirelli's recommendations, at a weight of about 64 kg, I should be running the 26mm tires at 83 psi / 5.72 bar and the 30mm tires at 65 psi / 4.48 bar. At recommended riding pressures, riding on the rollers with 30mm tires required an average power output of 170 watts, compared to 165 watts for the 26mm tires.

Now 26 mm tires see the benefit of 5 watts. Once again, at a smooth level, that is not thought of in aerodynamics. So how does a tight tire suddenly produce less rolling resistance than wide tires? Again, it probably has to do with casing stress and how the tire pressure affects the size and shape of the contact patch.

Roller Testing Final Result

Finally, our roller testing demonstrates that wider tires provide less rolling resistance than smaller ones when the same pressures are used. Yet, this advantage vanishes once riding pressures from the real world are considered. Let's look at some aspects and how they may affect choosing the ideal tire width for your bike. Real-world riding is crucial here because that's how we ride our bikes.

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⏰ Last updated: Mar 01 ⏰

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