Gravel's Next Frontier: The Rise of the Mid-Width, Fast-Rolling Tire

Tires are the one bike component that has the most influence on how a bike rides. For this reason, tires are a good tool for riders to use to fine-tune what their bikes excel at. This has never been so emphasized as in the gravel racing world where riders are tasked to race on all different types of surfaces all in the same race. High-level gravel racing has really grown a lot in the last 10 years, and over this time we have seen a wide range of tires being raced on; in the beginning, some riders chose 32mm road tires that were fast and light, while some riders would choose wider and reinforced gravel tires that provided more grip and puncture protection.

As this niche in the cycling world grows, it has gotten much more competitive, and with that, the gear has become more developed. The result of all the testing and debate has landed on the industry saying that lightweight mountain bike race tires are often actually the fastest choice for gravel. In the rest of this article, I am going to explain why this is the case, why I think this is going to be changing soon, and even some recent tire tech that supports my case.

The story of why gravel racers are finding themselves choosing mountain bike tires over gravel tires seems complicated, but in reality, it makes sense. At the start of gravel racing, cyclists would ride gravel on their road bikes with road tires. However, the lightweight road tires, in addition to not absorbing the bumps well, typically would have issues holding up to the rough surface.Thus, punctures were really common. This was the reason why when companies started to make gravel tires, they not only made them a little wider for the bumps, they also made them out of a tougher material that would not flat as easily.

As more and more people started to do scientific tests on the rolling resistance of tires, one thing was clear: the tougher material that is found on gravel tires not only makes the tire more resilient, it also makes them much slower to ride.

This left riders in a tough spot, as road tires are high-performance, but not suitable for gravel, and gravel tires are overbuilt from an all-out racing performance perspective. Luckily, there was another option; mountain bike tires are designed for rough terrain, and the race tires are made from a lightweight material that rolls fast too. Mountain bike tires were able to be made out of this lightweight material because of their wider width, which makes them better at absorbing the sharp rocks that typically cause flats on gravel.

As the industry starts to pick up on this trend, I think we will see tire companies start to respond by making tires that are better tailored to the requirements of gravel racers. I think there is definitely room for a tire that takes the principle of what makes the MTB tires fast, but puts them in a form factor that makes sense for gravel.

In addition to their low rolling resistance, MTB tires are suited okay enough for the biggest gravel races of the year because these races are virtually exclusively on gravel and flat, so the penalty for the aero and weight are offset by their rolling resistance on gravel. Albeit, aero and weight ultimately still matter, and these metrics are magnified when the bike is ridden over a mix of pavement and gravel. The average speed is higher, or there is more climbing involved. Mountain bike tires, unsurprisingly, lose their rolling resistance benefit quite quickly as the surfaces become smoother. Therefore, over more mixed surfaces is where a mid-width but lightweight tire would perform really strongly.

Coincidentally, most people ride their gravel bikes on mixed surfaces opposed to strictly on gravel, so there is in fact a big market for these tires. Even more, as gravel stages are being integrated into stages of road races like the Tour de France, they typically include lots of pavement, where a pure mountain bike tire would be too slow.

This summer, I predict that we will see more mid-width, lightweight, fast-rolling tires hit the market. As an example, last week Cervélo launched their new race gravel bike, which sneakily included a previously unreleased tire from Vittoria. The Vittoria Corsa Pro Control is a fast road bike tire, which is listed on their website to be offered up to a 34mm width, which is considered too narrow for most gravel riding. However, the new Cervélo Áspero comes with this tire in a 42mm width, placing it solidly in gravel territory. I suspect that this marks the first of many companies who are going to expand their road racing tire model up to wider widths while maintaining the low weight and rolling resistance construction of the tires.