- More riders are experimenting with gravel bikes at South Africa’s most punishing mass participation off-road cycle races.
- But do these bikes have a natural advantage? The only way to know is by racing them against mountain bikes.
- At the brutal 36ONE MTB Challenge, a young rider surprised many with his bold equipment choice.
Gravel bikes are a cycling trend that just doesn’t fade, with the segment continuing to grow globally. These bikes, which look like road bikes with larger tyres, are a curiosity to many. But not everyone is convinced of their superiority in the off-road mountain bike racing scene.
Although a few brands offer gravel bikes with short-travel forks and a bit of rear-suspension, most gravel bikes are harsh. Unlike mountain bikes, they lack the comfort of proper suspension. And they roll much narrower tyres, further reducing any element of cushioning terrain.
Despite the potential for discomfort, more gravel bikes are rolling into the start chute at mountain bike events. Organisers have adapted to the trend with rule changes, allowing gravel bikes to race for 'official' timing and places. But are they really better rolling over South Africa’s often corrugated and rocky off-road cycling routes?
Proving the gravel bike speed concept
Wayne van der Walt proved the point by winning this year’s 36ONE MTB Challenge. Regarded as a nightmarishly challenging event, it routes for 361 km, linking all the most difficult bits of dirt road and off-road mountain passes surrounding Oudtshoorn.
Van der Walt rode to victory in the event by a margin of nearly 23 minutes. His finishing time for the 361km route was 15:37.52. What made Van der Walt’s win notable was that he chose to ride a drop handlebar gravel bike, without any suspension, unlike all his rivals.
A typically unpredictable Garden Route cold front edged inland, making for a freezing and wet event. These conditions played to the advantage of Van der Walt’s bike choice. Gravel bike tyres roll faster on muddy Karoo dirt roads compared to the tread drag of a traditional mountain bike tyre.
Bigger gravel tyres - but not too big
Product specialists have identified the need for larger volume gravel bike tyres, with bike designers creating more space for wider rubber with each frame iteration. Not only have gravel bike tyres increased in size, but the tread patterns have also developed, with excellent options for shedding mud.
It’s worth noting that in short-court cross-country mountain bike racing, riders often prefer a narrower tyre for extremely muddy routes. Why? Because narrower tyres exert more point pressure on a muddy trail surface, effectively 'cutting' into it to access better grip beneath.
Getting low - to go faster
Beyond the benefit of his narrower tyres in the muddy conditions, Van der Walt’s gravel bike also reduced his aerodynamic drag along the 361km route.
The aero position that riders can adopt with drop handlebars makes a significant difference when riding long distances – especially into headwinds, which were a theme on parts of this year’s 36ONE MTB Challenge route.
Wayne van der Walt’s win at one of South Africa’s most extreme off-road cycling events has validated that gravel bikes are indeed faster than mountain bikes if you can handle the bumpy ride… Provided the racing in mostly open terrain, without extremely rocky sections.