Gravel bikes are making inroads onto mountain bike trails all over the country, it’s time to shave our legs, pull on a tattoo sleeve and offer our totally unbiased opinion
Until very recently, gravel was something you shovelled onto the driveway. Now though, and in case you’ve been burying your head in a pile of it recently, it’s a kind of riding. One that blurs the lines between XC mountain biking, cyclocross, and road riding. Gravel riding proponents (and they now include once mtb-only stalwarts like Kona, Evil, and most recently, YT Industries) boast it delivers the kind of speed over the ground thrills of a road bike, over natural terrain and flowy singletrack. The detractors have it the other way; they’re road bikes out of their element, and the best way to spoil a good mountain bike ride. What you want is one of the best XC full-suspension or hardtail bikes instead.
So who has it right? Time for us to step in, and deliver a verdict on gravel riding… totally unbiased of course, never mind the fact our name is Mountain Bike Rider.
Gravel’s high ground
Let’s get serious for a moment though, and consider whether there actually could be some advantages to riding a gravel bike on certain trails. We often hear how mountain bikes are so good now they dumb down trails that were once difficult or exciting. Could gravel bikes fill that space, delivering an even faster and more thrilling ride than the best XC bikes, covering more ground and with less effort?
Bike companies are smart too, it’s not a coincidence that gravel bikes now have lots of the components that make mountain bikes great. Suspension, disc brakes, squidgy tyres. We’ll get to that next, but we wouldn’t be surprised if the gap between the two disciplines was smaller than we first thought.
Gravel riding is also one of the biggest growth markets for bike sales in Europe. Bucking the trend of declining sales following the post-Covid slowdown, gravel bike volumes were up 8% in 2022 from the previous year, according to the Bicycle Association. And they’re up a huge 59% since 2019. This prompts the question, is there something we’re missing out on?
Step forward two bikes from Specialized, designed to cover ground as quickly as possible but with slightly different ways of going about it.
Both use a full carbon frame, but the Diverge STR Expert hase something Spesh calls Future Shock delivering 30mm of rear travel and 30mm on the front. Suspension then, but nothing like on a mountain bike, where the wheels are suspended from the frame – here it’s the rear triangle that moves, meaning you’ll only get the rear-wheel advantage when sat on the saddle.
The Epic Hardtail Comp meanwhile has a normal suspension fork in the shape of the RockShox Reba RL, and a fixed rear end. It’s also using a full-carbon frame. In terms of geometry the Epic has a slacker head angle and a longer wheelbase, which should help it out when descending. It’s heavier too, but not by much, but with its heavier wheels and bigger volume tyres it’s bound to go slower on the climbs.
Both bikes have disc brakes with 160mm rotors, except the Epic’s front wheel which gets a 180mm disc. The bikes have knobbly tyres, the difference being the Diverge uses a 700×42 tyre and the Epic 29×2.35in – same circumference then, but the gravel bike’s rubber is less than half the width.
|Epic Hardtail Comp (Large)||Diverge STR Expert (56cm)|
|Effective SA @770mm||75.1°||68.0°|
I chose the mellowest trail I could think of, with mostly-smooth terrain and a gradual gradient only broken by a small climb in the middle. It’s exactly the trail we were riding 20 years ago on bikes probably shorter, steeper and higher than the gravel bike here today. In this way I’d hoped to tilt the test in the gravel bike’s favour, and thereby overcome my natural bias towards MTBs. Getting back up was via a gradual fireroad climb, I metered my efforts here to keep things fair by sticking to a 140-bpm heart rate. I used an A-B-A testing pattern, with two runs on the Diverge, four on the Epic, then two more on the gravel bike.
As expected, the Diverge consistently beat the Epic on the climbs, letting me pedal up 6% faster and shaving 30 seconds off the time. Descending was far more interesting though, the Epic eviscerated the Diverge’s times by an average of 9% faster, or 20 seconds.
Both bikes felt really adept on the climbs and carried great momentum. The gravel bike felt the best, with a stretched out but comfortable seated position, and the Specialized design actually cossetted you better than the Epic’s fixed back end. In contrast the Epic tended to bounce when pedalled hard through rocks or bumpy parts.
The Diverge felt lighter and rolled more easily, and when the Epic’s turn came round this made us inadvertently push harder, probably to match the speed of the Diverge. I was constantly having to check my heart rate and tone it down. The gravel bike was slightly over geared though, with a 40t chainring a bit of a stretch on the steepest part of the climb, to the Epic’s 34t.
Going down was a different story, the Epic felt much more stable, easier to maintain momentum and push for speed. Most importantly, I could pump the bike into the trail for free speed, bunnyhop over obstacles more effectively, and take more abuse without being shaken off. In contrast the Diverge gets hooked up on everything going, stalls on all but the flattest sections of trail. It feels fast but really that’s because there’s just so much going on.
What we found out
The first thing to note is just how hard it is to control a bike when you can’t get your saddle out the way and distribute your weight properly. This applies to both bikes of course, which both have fixed saddle heights, but the gravel bike is doubly affected because the narrow bar means you can’t move your weight around at the front either. This was one of the biggest differentiators between the bikes, and which ultimately meant I could descend faster on the Epic.
Riding a gravel bike is a nervous experience, and I don’t just mean for me as a relative newbie to the idea. Ride the bike downhill with your hands on the hoods and it feels like one unexpected root or rock could snatch the bars from your hands. Switching to the drops means you won’t lose your handhold, but with its tiny reach your weight is too far over the front and going over the bars is feels a distinct possibility. The clever rear suspension is rendered useless when you’re stood up and descending too.
The mountain bike felt much faster, and of course it proved so too. The combination of bigger volume tyres, a suspension fork with superior damping and better geometry and components designed for riding in the attack position made the difference.
The verdict then is that the Diverge is great for fire roads and proved faster and (surprisingly) more comfortable than the Epic when climbing. It’s also better and faster than anticipated on smooth and gradual singletrack descents, putting in decent times. Fast it might be, but it’s a white knuckle ride and I felt way out of my comfort zone. Anything more than the smoothest of mellow trails, and the Epic eats its lunch, as expected.
There are some really important takeaways from this little test then. First is that it’s so important to get the right bike for the trails you ride. An all fire road ride would have seen the Diverge ace the test, while chunkier singletrack would have confounded both bikes. Second, bike setup is as important as it’s ever been, and getting the right tyre pressure and saddle height made a world of difference to how both bikes rode. Finally, and irrefutably, mountain bikes are better than gravel bikes. The end.