Gravel riding has surged in popularity, and with it, the question: gravel bike or mountain bike? As someone who’s been exploring gravel roads and beyond long before it was trendy, I’ll delve into the nuances of choosing the right bike for your gravel adventures.
What Exactly is Gravel Riding?
For some, gravel riding conjures images of pristine, well-maintained gravel roads, perfect for a smooth spin. And indeed, that’s one facet of it. But for many, including myself, “gravel riding” is much broader. It’s about adventure, linking diverse terrains – gravel roads, pavement stretches, rugged fire roads, two-track paths, and even jeep or ATV trails. It’s reminiscent of childhood bike explorations, where the surface was secondary to the journey itself. Your personal definition of gravel riding is crucial in determining the ideal bike setup. Just as you wouldn’t choose a downhill bike for gentle trails or an XC bike for extreme downhill, the terrain dictates the tool.
Flat Bars vs Drop Bars: Control vs. Efficiency
Wide, flat bars undeniably offer superior control and stability, especially on technical mountain bike trails. However, on less demanding terrain, flat bars often lead to a more upright, less aerodynamic riding position, hindering speed and efficiency. Furthermore, hand position versatility is limited with flat bars. On longer rides, this lack of options can significantly impact hand comfort and fatigue.
The choice between flat and drop bars hinges on your riding style and terrain. If your gravel rides are shorter, incorporate frequent technical sections, or prioritize maneuverability, flat bars might be advantageous. Conversely, for long days in the saddle, primarily on less technical gravel, the aerodynamic and comfort benefits of drop bars become increasingly apparent.
Mountain Bike Frames vs. Gravel Bike Frames: Geometry Matters
Mountain bike frames are typically characterized by slack geometry, longer reach, and a higher bottom bracket compared to gravel frames. While beneficial for aggressive trail riding, these features become drawbacks on gravel. Slack geometry on extended climbs can make it harder to maintain a straight line, requiring more effort. Mountain bike frames are also generally overbuilt and heavier to withstand harsher impacts, adding unnecessary weight for gravel riding.
Attempting to convert a mountain bike into a drop-bar gravel bike often results in twitchy steering due to the required short stem to compensate for the longer reach. While drop-bar mountain bikes exist, like the Salsa Cutthroat, they often employ gravel-oriented geometry, potentially making them a more versatile choice than many standard gravel bikes.
Gravel Suspension vs. Mountain Bike Suspension: Different Needs
Suspension needs vary dramatically between gravel and mountain biking. Gravel suspension is designed with minimal or no damping. This is because effectively absorbing high-frequency vibrations on gravel necessitates a suspension system that can react very quickly and freely. Consequently, gravel suspension underperforms on true mountain bike trails, easily bottoming out and exhibiting a fast rebound, leading to a “pogo stick” effect.
Mountain bike suspension, in contrast, features significant compression and rebound damping. Riding a mountain bike on gravel often reveals that the suspension remains largely inactive until encountering substantial obstacles like large rocks or roots.
The optimal suspension type is dictated by your gravel riding environment. For rougher doubletrack, jeep trails, and singletrack, mountain bike suspension is the clear winner. However, on smoother gravel roads, it simply adds unnecessary weight with minimal benefit. Gravel suspension is lighter and better suited for most gravel terrains, excluding singletrack. Personally, for most gravel riding, I find larger volume tires and a Redshift suspension stem provide more effective comfort than a dedicated suspension fork.
Tires: Size and Tread are Key
This is where the lines blur intriguingly. Unless your gravel rides are heavily weighted towards pavement, faster XC (cross-country) tires will generally outperform gravel-specific tires on any off-road surface. This is a realization increasingly adopted by top professionals, exemplified by Dylan Johnson’s use of 2.2″ Race King tires at Unbound gravel race. Even Lachlan Morton opted for a 50mm front tire on his winning bike.
The core principle is that lower volume tires are slower on gravel, despite the prevalent use of 42-45mm tires among many professionals. In my experience, 50mm should be considered the minimum tire width for true gravel riding, unless pavement dominates your routes.
Unfortunately, tire clearance is a limiting factor for many gravel frames. Most won’t accommodate tires larger than 47mm. This is where a mountain bike, or a drop-bar mountain bike specifically designed for larger tires, might present a superior option.
The Bottom Line: Ride What Suits You Best
Ultimately, you can ride nearly any bike on gravel. However, the ideal setup, balancing comfort and efficiency, leans towards a drop-bar bike capable of fitting 50mm or wider tires. Yet, depending on your specific riding style and terrain, a flat-bar XC mountain bike might be preferable.
Furthermore, an XC mountain bike might simply be more enjoyable for certain riders. While it might not be the fastest option, enjoyment isn’t always solely defined by speed. The most important advice is to ride the bike that brings you the most happiness and best suits your individual needs and riding style.
