For years, many gravel cyclists have turned to wider mountain bike tires, believing bigger equals faster and more comfortable on rough terrain. But new, rigorous testing is turning that idea on its head, revealing a surprising key to speed: the suspension fork.
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Performance engineer Marc Graveline, known for his work with WorldTour teams and aero tech, recently conducted extensive testing with pro gravel racer Hannah Shell ahead of the demanding Unbound race. Their findings challenge the common wisdom: on rough gravel, a suspension fork paired with narrower gravel-specific tires proved faster than even wide mountain bike tires used with a traditional rigid fork. This isn’t just about feel; the testing showed significant, measurable performance gains.
Challenging the Wide Tire Trend
Gravel riding sits right between road cycling’s sleekness and mountain biking’s ruggedness. Lately, the trend has leaned towards borrowing from the mountain bike world, especially by fitting larger, wider tires for better grip, comfort, and speed on choppy surfaces. Previous tests have supported the idea that these wider tires can be faster.
However, Graveline’s detailed analysis adds a crucial “but.” He found that while mountain bike tires were indeed faster than narrow gravel tires when both were used on a rigid fork, the results flipped completely once a suspension fork entered the picture.
With a suspension fork, gravel tires (specifically, a 45mm front and 40mm rear setup was tested as fastest) outperformed not only gravel tires on a rigid fork but also the wider mountain bike options. This highlights a critical interaction between components that wasn’t fully appreciated before.
How They Uncovered This Speed Secret
Graveline’s testing wasn’t just a casual ride. He used a structured, repeatable method combining real-world riding with advanced sensors. This included a custom drag measurement system and IMUs (Inertial Measurement Units, which track movement and acceleration).
Think of it like solving a complex science problem. Cycling performance is influenced by many factors: air resistance, how easily the tires roll, drivetrain efficiency, and energy lost to vibrations from rough ground. By carefully measuring things like power, speed, and wind, and using structured testing loops, they could isolate and measure how different setups performed.
The findings came from two intense four-day testing blocks focused on optimizing Hannah Shell’s setup for Unbound. Graveline applied the same detailed approach he uses for aerodynamic testing with top-tier road teams. The testing involved days focused solely on understanding the suspension fork’s impact, and then re-testing tire setups with and without suspension to compare directly.
Hannah Shell's Cervelo Aspero bike with suspension fork and tested tire setup for Unbound
This rigorous process allowed them to see exactly how much faster one setup was over another, not just anecdotally, but with solid data showing measurable wattage savings.
Why This Matters for Your Ride
The big takeaway from this testing is that performance on rough gravel isn’t just about picking one component in isolation, like the widest tire you can fit. It’s about how the entire system works together. A suspension fork changes how the tire interacts with the ground, allowing a potentially less bulky tire to maintain better contact and roll more efficiently because the suspension handles the bumps.
This suggests that for riders tackling truly rough gravel, investing in a suspension fork might be a more effective path to speed and comfort than simply upsizing tires. It opens up new possibilities for optimizing bike setups, moving beyond the rigid frame and tire choice being the primary focus.
This testing builds on the ongoing evolution of gravel tech understanding, reminding us that sometimes the fastest setup isn’t the most obvious one, and detailed testing can reveal surprising performance advantages.
