Separating categories in off-road cycling can be tricky. To non-riders, and even riders beyond, mountain bikes have suspension and gravel bikes don’t. But that isn’t always the case.
The demand and innovation regarding gravel bikes have remained constant. Many gravel bike products were at the recent Sea Otter cycling show, an event which acts as a value progenitor for industry trends. Some were easy to understand, like tread-specific gravel bike tyres. But gravel bike suspension, either fitted or integrated into frames, remains a curiosity to many and is deemed unnecessary by some.
There is a curious correlation between gravel bike suspension innovations and the early phase of mountain bikes. In the 1990s, when mountain biking phased through its most adventurous and limitless period of innovation, headshocks, flex stems, and softail rear triangles were all marketed as suspension solutions.
Evaluate some of the innovative suspension features on contemporary gravel bikes, and there’s a definite similarity to 1990s mountain bikes. Specialized’s Future Shock is a modern interpretation of the mountain biking flex-stem idea of suspending the rider, not the bike, to absorb terrain textures and impacts. It’s the same with elastomers dampers, shaped into the rear triangle, as seen most recently on Lapeirre’s Pulsium and BMC’s URS gravel bikes. All this has raised the question, are gravel bikes old-school mountain bikes?
The issue of ‘miniaturised’ forks
Specialized Women's Diverge E5 Comp Detail Future Shock-6.jpg, by Rachael Gurney
Gravel bikes with a softail rear triangle or headshocks aren’t that revolutionary. But the idea of short-travel forks blurs the distinction between gravel and mountain bikes. And the market for suspension forks with 30-40mm of travel has exploded due to gravel bikes.
All the most influential brands in cycling suspension now offer gravel-specific forks, with travel options down to 30mm. And that is where the question about gravel bike suspension and terrain absorption becomes the subject of debate.
2023 Dirty Reiver bikes Rå bikes valravn-4.jpg, by Suvi loponen
The margin for setting compression and rebound damping with a 30mm air fork, is tiny. And you are inducing sag to the frame’s geometry, which means the angles you value regarding your gravel bike’s design will alter as the suspension compresses and bops. If you think critically about the issue, in many cases, gravel bikes aren’t designed for sag like mountain bikes are, with their much slacker head angles.
Gravel bikes are often loaded with frame bags and ridden over vast distances on adventure routes. That means a small suspension fork is working very hard for its living, with the possibility of increased maintenance cycles.
What about a fixed ‘suspension’ fork?
If hand, wrist and shoulder fatigue are the issues when rolling along on that 150-mile weekend adventure route, doesn’t a Lauf fork make the most sense?
Manufactured in Iceland, the Lauf Grit SL design offers 30mm leaf-sprung suspension without seals or service requirements. It lacks adjustability, but as I’ve mentioned, the possible adjustability of a 30mm travel air fork is pretty limited. The Lauf will absorb some of the mid-frequency terrain texture that often triggers rider fatigue on long gravel route ride.
Tyres are the primary suspension feature on any mountain or gravel bike. And the gravel bike market has seen an extensive increase in available tyre choices, both in casing size and tread pattern. Spending money on a potentially fragile 30mm air-sprung suspension fork, without rolling 700x48c tyres, is pointless. When considering gravel bike suspension, the first thought should always be to optimise casing damping at low pressures, which means running the biggest volume tyres you can.
The Lauf fork is an excellent solution for gravel bike riders who log significant yearly mileages and are mindful of the suspension cost of traditional suspension. These Icelandic carbon forks can roll the largest gravel bike tyres and offer 30mm of maintenance-free suspension. You get the best of both worlds without the compromise of effectively riding a miniaturised mountain bike fork.
Tyres might matter more than suspension
Not all pro-riding set-ups have validity for weekend warriors, but it’s worth noting how bikes are configured for the world’s most demanding gravel riding events.
Africa has the world’s most arduous dirt roads, with equally demanding gravel bike events. Gravel races like the Migration gravel race in Kenya or South Africa’s Munga ultra-endurance solo ride. The winners of these events aren’t on gravel bikes with integrated or fitted suspension. But they are all rolling the largest possible gravel tyres.
The Munga is arguably one of the world’s most brutal off-road events. It routes across South Africa’s Karoo desert, rolling on some of the world’s most iconic and corrugated dirt roads. Riders have 120 hours to cover 620-miles.
Kevin Benkenstein is a multiple Munga finisher and winner. His gravel bike configuration? No softail. No suspension fork. Not even a clever headshock. But Kevin does roll large-volume mountain bike tyres, choosing to squeeze Maxxis Rekon Race 29x2.4s into his titanium gravel bike frame.
If you aren’t riding African-grade dirt road corrugations, chances are, you don’t need a gravel bike suspension fork. But you will always benefit from the ride comfort and ‘suspension’ of large-volume tyres.
Droppers make more sense than gravel air-forks
YT Szepter gravel bike dropper post, by YT Industries
Gravel bike suspension might be a touch difficult to fathom and justify, but what about dropper seatposts? These have some of the suspension fork’s disadvantages regarding maintenance but some genuine and usable riding benefits.
The dropper seatpost enhances descending stability and confidence. The lower a gravel rider’s centre of gravity, the more control they’ll have when descending. When the first dropper seatposts were fitted gravel bikes, a faction of the off-road riding community considered them superfluous. They were judged as a pure mountain biking component, out of place on gravel riding routes. But in practice, the dropper seatpost has terrific applicability for gravel riders.
Descending speeds on long gravel route descents can be high. And terrain surfaces are often loose shale and pebbles. Or they are textured with corrugations and ruts. Any terrain texture at high speeds can trigger front wheel deflection and a loss of steering control. And that’s where positioning at a lower centre of gravity on the bike is advantageous, helping gravel bike riders correct and stabilise their bike.
Gravel droppers and maintenance
YT Szepter gravel bike, by YT Industries
Gravel bike dropper seatposts have a similar design profile to gravel bike suspension forks. They feature small diameter stanchions and seals to fit in the narrower tube sets of a gravel bike compared to a mountain bike. That means more potential wear and play developing over time, but worth the sacrifice.
Some brands, like DT Swiss, build simpler gravel bike droppers with coil-sprung internals. These dropper seatposts promise to be more resistant to developing mechanical play and should last for many seasons without requiring expensive maintenance.
Gravel bikes live in a design spectrum between road and mountain bikes. That’s a given. They incorporate elements and influences from both. And that’s why there is more scepticism about gravel bike suspension than gravel bike dropper seatposts. You aren’t going to see softail suspension or headshocks at the Tour de France anytime soon. But the expectation is that dropper seatposts might happen, to aid pro riders on those terrifyingly steep and fast Alpine descents.
What’s the ideal gravel bike set-up for adventurous routes, if you are a rider mindful of budget and future maintenance requirements? That would probably be a gravel bike with Lauf’s Grit SL fork, rolling 700x48c tyres and a fully mechanical coil-sprung dropper seatpost, like the DT Swiss 232.
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