The gravel racing scene has evolved massively in recent years. The trend towards significantly wider tires is impossible to ignore, and it’s something we recently explored in depth in our big gravel tire group test. Just a few years ago, slim 40 mm tires were considered the benchmark. Now, 45 mm rubber and, depending on the race, even XC tires measuring over 50 mm wide have become the norm. While 32” wheels promise similar performance gains, they also rewrite the rulebook entirely. Moving to this wheel size demands far more radical solutions and introduces an entirely new level of engineering challenges.
That becomes obvious when you look at the two Scott riders putting the prototype through its paces at UNBOUND. Swiss ultra-endurance specialist Robin Gemperle, standing at 1.88 m, will presumably be riding a large frame where the huge wheels still look reasonably proportional. New Zealander Cameron Jones, at around 1.80 m tall, is a far better benchmark for the average rider. That’s exactly where the technical limitations start to appear.
Particularly with medium and smaller frame sizes below 56 cm, the concept quickly runs into packaging issues. The enormous wheels force engineers to use a much shorter head tube to keep the already towering stack height under control, which often leaves aggressively slammed stems as the only viable solution. Combine that with the goal of maintaining a compact, aggressive wheelbase for sharp handling and toe overlap with the oversized front wheel becomes almost inevitable.
The bikes ridden by both athletes are built around a specially developed Scott RC Gravel 32 frameset and roll on huge custom-built wheels fitted with 50 mm Schwalbe G-ONE RX tires. The component choices are particularly fascinating because the industry still has no established standards for this wheel size.
While Cameron Jones is running a mix of Shimano XTR components and Dura-Ace shifters paired with ultra-short 160 mm cranks and custom Industry Nine wheels, Robin Gemperle lines up with SRAM’s RED XPLR 13-speed groupset. Unsurprisingly, both riders are full of praise, especially when talking about the supposedly revolutionary cornering traction.
Officially, Scott stress that these are purely prototype bikes and will never reach production in their current form. But it’s worth reading between the lines here. These bikes required genuine, eye-wateringly expensive carbon moulds to be produced. It’s hard to imagine any manufacturer investing that level of financial and logistical effort, opening entirely new tooling, purely to create a feasibility study destined to sit in a display cabinet. History tends to tell a different story: what wins races like UNBOUND usually finds its way into production sooner or later.
We already had the chance to test a similar feasibility study developed by design studio Faction Bikes a few weeks ago, and you’ll be able to read that review very soon here on our site. Time and again, prototypes have shown the same pattern: what succeeds in the World Cup or at major races like UNBOUND eventually ends up on shop floors too.
Blessing or pointless hype?
The announcement comes at exactly the moment the 32” debate, which we explored earlier this year in our The MIRROR format, is spilling over from mountain biking into the gravel scene. From a purely physics-based perspective, the theoretical advantages on brutal courses like UNBOUND are hard to ignore.
Rollover performance and comfort: The noticeably shallower attack angle allows the bike to glide far more smoothly over sharp rocks and deep potholes. On the endless straight roads of Kansas, that alone could make a decisive difference in reducing fatigue over time and helping riders stay on pace deep into the race.
Flywheel effect: Once up to speed, the larger rotating mass carries momentum exceptionally well. Combined with the stronger gyroscopic stabilisation of the bigger wheels, this promises maximum composure and stability on high-speed descents.
That said, these advantages come with major physical and geometric compromises, exactly as we predicted back in January. We saw it not only with the Faction Bikes prototype, which was specifically designed to create the smallest feasible frame size possible, but now also with Scott’s approach. A tire circumference that’s roughly 10% larger results in noticeably slower acceleration and reduced agility. The wheel size also forces dramatic geometry changes, including longer chainstays, increased risk of toe overlap and altered cockpit proportions.
That’s why our stance remains clear: for high-end bikes and extreme races like UNBOUND, where the courses are fast rather than especially tight or steep, this concept could make sense in the pursuit of marginal gains. For the wider market, however, it feels like an unnecessarily risky trend and does little to address the industry’s deeper structural issues, which we recently explored in our editorial on the 41 Leadership Summit in Leonberg.
Even if the required changes in the gravel and road segments remain relatively limited compared to mountain biking, essentially requiring little more than new tyres, rims and spokes, the added complexity is still significant. It creates yet more variants and drives up tooling costs for manufacturers. In the current market climate, additional SKUs reduce resilience across the retail sector rather than strengthening it.
Conclusion
Scott are using UNBOUND Gravel as a high-profile proving ground to showcase what’s technically possible. Whether 32” wheels will genuinely reshape gravel racing remains highly questionable given the extreme geometry compromises and the looming threat of yet another standards war. The coming weekend, and the years ahead, will reveal whether the concept delivers or remains a niche solution for a very limited audience. Either way, we’re excited to see how the prototypes perform on the gravel roads of Kansas and which manufacturer will be first to launch a production 32” gravel bike.
Find out more at scott-sports.com.
Find out more at scott-sports.com.
Did you enjoy this article? If so, we would be stoked if you decide to support us with a monthly contribution. By becoming a supporter of GRAN FONDO, you will help secure a sustainable future for high-quality cycling journalism. Click here to learn more.
Words: Jan Fock Photos: Scott