With gravel bikes and gravel events like Dirty Kanza and Crushar in the Tushar quickly growing in popularity, which type of bike works best for getting off pavement?
Events like Utah’s Crushar in the Tushar have helped propagate gravel road riding. Photo Courtesy Crushar in the Tushar
You’ve ridden to the “Pavement Ends” sign on your road bike and turned around more times than you can count, and always wondered where it leads. But your 23c road tires and caliper brakes are no match for the small rocks, ruts and loose dirt that runs for miles. A cyclocross bike would easily be able to handle it, but you just heard about these cool new ‘gravel bikes’ and are conflicted.
Along with enduro and fat bikes, gravel bikes are the hottest niche in the bike industry right now. So how do cyclocross bikes, road bikes and these new dirt-ready machines differ in geometry, tire clearance and intended use?
Like anything in life, there is a proper tool for every job. So the first question that must be asked is what will your primary riding be? Will you primarily race cyclocross with occasional gravel and road riding? Are you set on winning the Dirty Kanza? Or do you just want a good all-around bike for recreational use that can handle road, dirt and cyclocross with equal aplomb?
Think of a gravel bike as a cyclocross bike with more relaxed geometry and longer tube lengths for a more comfortable ride, while true cyclocross bikes are designed to accelerate fast and corner quickly at lower speeds. Therefore, traditional cyclocross geometry features taller bottom bracket height, shorter chainstays, a shorter top tube and a steeper head angle.
Although this setup is great for racing ’cross on tighter, lower-speed courses, when it comes to wide open gravel roads where speeds top 35 mph on downhills, the higher center of gravity and twitchier steering can make for an unstable feeling ride.
Mavic PR man Zach Vestal knows this feeling first hand. He recently raced Utah’s Crushar in the Tushar on a traditional European-style cyclocross bike. “It was awesome; a completely unique experience unlike anything else I’ve ever done,” he said. “But I definitely could have benefited from a more compliant frame and slacker angles for better stability on the high-speed downhill sections.”
Geometry is one of the core differences between each style of frame, with race-bred cyclocross and road geometries being more aggressive than gravel oriented bikes. However, there are numerous race-oriented cyclocross bikes from North American brands such as Raleigh, Ibis, Specialized and Moots that have lower bottom bracket height for improved cornering stability and slightly less aggressive geometry for all-around use.
But for those without aspirations of dominating their local cyclocross scene, a gravel-specific bike might be a better, more comfortable option.
The new Giant Revolt is one among many new gravel road-specific bikes to hit the market this year.
“From a geometry perspective, a gravel bike like the Giant Revolt does not need to be as quick handling as a race-oriented cyclocross bike,” said Giant’s James Hibbard. “Rather than being designed to jump barriers or shoot through a field of riders, a gravel bike has geometry that is more stable, resulting in handling that is more predictable and demands less of a rider. Compared to an endurance road bike, a gravel bike will be even more relaxed in geometry and in most cases have a shorter cockpit. One could race a criterium on an endurance road bike, but a gravel bike is not the ideal tool for crit racing. It is too slow handling and designed to track better at lower speeds than a road bike.”
Trek does not offer a gravel-specific bike, but does have four models that can handle multiple types of terrain. The Domane is an endurance road bike with an Isospeed Decoupler for better shock absorption. For those who need bigger tire clearance, the Crockett, Cronus and Cross Rip offer disc brakes and three unique geometries depending on the rider’s intended use.
But if you could have only one, which is best for gravel road riding?
“I would go with the Cronus or Crockett,” said Michael Mayer, Trek’s road product manager. “I race cyclocross, but those two bikes can also do gravel and road quite well. If I was more of a commuter and casual racer, the Cross Rip would be a great utility bike option.”
BMC offers what they consider a true all-around bike, the GF02 Disc. Even though it was never intended as a pure cyclocross bike, it has enough clearance for 35c tires and features concealable fender and rack mounts for commuting and messy winter road rides.
“It’s probably the most versatile bike in our lineup,” said Devin Riley, BMC USA director of marketing.
In addition to geometry, there are other aspects to consider when choosing a bike for off-road duty, including braking, drivetrain and durability.
“Gravel bikes need to be even more durable than cyclocross bikes, adding weight to the bike,” said Giant’s Hibbard. “Races like the Crushar or Dirty Kanza are really hard on bikes, and parts spec on a race-level cyclocross bike or high endurance road bike will not square up with races that hard on equipment.”
The Dirty Kanza is another popular off-road road race that’s gained notoriety. Photo By Andrew Vontz
Drivetrain setup varies quite a bit depending on intended terrain, and Shimano product manager David Lawrence sees his company spec’ing several different gearing combinations.
“46-36 front chainrings with an 11-32 eleven-speed rear cassette is quite popular for cyclocross and gravel,” said Lawrence. “For those doing more road, 50-34 or 52-36 up front is a better option.”
Perhaps the biggest development on the horizon for shifting will be the integration of Di2 electronic shifting, offering reliable performance no matter how muddy the conditions. Shimano recently released their new Di2-enabled ST-R785 hydraulic disc brakes for road, compatible with any E-Tube enabled Ultegra 6870 or Dura-Ace 9070 drivetrains.
“The derailleur tells the shifter how many speeds there are, so people who already have a Di2 system only have to replace the shifters on their drivetrain to get both hydraulic disc braking and electric shifting,” said Lawrence.
An added benefit of Di2 is remote shift points, enabling you to shift either from the hoods, the drops or even the tops. And with programmable software, Di2 can be customized to shift two, three or multiple gears when the shift button is held down.
Since the UCI legalized disc brakes for cyclocross, nearly all new cyclocross bikes and most gravel-specific bikes now offer disc braking. There are still some who believe cantilevers are lighter, simpler and more effective, especially in extreme conditions. But professional cyclocross racers like Jeremy Powers of Team Rapha-Focus have made up their minds on the subject.
“I’ve been on disc brakes for two years now, and I won’t be switching back,” said Powers. “The ability to stop when I want and the added control I have on descents is far better than cantilevers, especially on carbon rims.”
SRAM launched a full hydraulic disc brake system for road bikes earlier this year. Shimano quickly followed suit.
Over the past two years Powers has worked with SRAM in testing and improving the quality and durability of brake pads for cyclocross racing, trying different metallic compounds and pairing them with solid disc rotors which don’t wear down pads as quickly.
“Cantilever brakes have pretty much reached their max for perfectibility,” added Powers. “Although disc brakes already work exceptionally well, there’s still a lot more room for improvement, which is exciting.”
The bike industry — as well as most outdoor sports industries — tend to make us feel inferior about what we have in our garage, convincing us to go out and buy something new that might not necessarily be that much better. So besides subtle geometry tweaks, is there really that much of a difference between a cyclocross bike, a gravel bike and an endurance road bike?
“To me, the largest difference between these three types of bikes is tire clearance,” said professional mechanic Tom Hopper, who works with Powers. “A wider tire in a race like the Crushar has many benefits including control, comfort and puncture resistance. The most versatile bike would be a disc cyclocross bike. You have the option of running any tire size you want for the conditions and you have the best braking possible.”
Jon Cariveau of Moots echoes Hopper’s sentiments. “It really all comes down to the tire size needed for the event. If someone came to my house and said ‘we are taking all of your bikes, you get to keep one’, it would be my Psychlo X cyclocross bike. I use it for all of my riding except for the really nasty trails I ride on my mountain bike. I can race on it, commute, road ride, grocery get, add fenders, travel…you name it.”
Powers is also on board. “I don’t see a massive difference between a cyclocross bike and a gravel bike,” said Powers. “From my standpoint, if I can’t do it on a cyclocross bike, then I should be on my mountain bike.”
So perhaps it all boils down to how fast you want to go. “Riding on gravel is nothing new,” said Mayer. “I think the organization of specific gravel events is where things are changing. The last gravel event I did was on a Domane, but at that race there was every bike imaginable. The folks in front were on road or cyclocross bikes, those in the middle were on more gravel-specific bikes and the folks towards the back were on mountain and dual sport bikes. But the one constant was that everybody was having a great time.”
And in the end that is what it’s all about.