Hardly any tech topic has sparked more discussion this year than gearbox drivetrains with belt drive in the Downhill World Cup. What was still considered a bold move by a few small teams in 2024 has developed into a serious trend within just one season. Driven by GATES, who aim to redefine the future of drivetrains with their Carbon Drive technology in combination with a Pinion gearbox. And they’ve underlined this with a clear message: whoever wins an Elite UCI Downhill World Cup with a GATES belt drive will walk away with €100,000 in prize money – a substantial sum in the DH racing circuit. This reward has brought the belt drive and the associated gearbox to the big stage and fueled widespread debate.
With Atherton Racing and Intense Factory Racing, two major, successful teams have now officially switched to gearbox drivetrains. In total, four teams are competing in this year’s World Cup using the belt-driven concept. Former World Champions and World Cup and National Championship winners like Harriet Harnden, Charlie Hatton, and Reece Wilson are relying on the system from GATES and Pinion. No bike with a belt drive has won a Downhill World Cup yet – but the question no longer seems to be if it will happen, but when.
But let’s put racing aside for a moment. We’re after more: we want to know what’s really behind the hype. Is it all just a clever marketing stunt – or a technically superior solution that, with the right development, will soon be found on many of our bikes? To find out, we took a trip to Wales, visited Charlie and the Atherton family, checked out the development of their new Atherton A.200.G, spoke with product managers and engineers, and swung a leg over the fascinating bike ourselves. All to answer one crucial question: does a gearbox drivetrain with a belt also make sense on trail and enduro bikes and beyond the World Cup circuit – for you, for us, and for the broader cycling community?
What are the pros and cons of a gearbox drivetrain?
Let’s start from the beginning: a gearbox drivetrain can be implemented using either a belt or a chain. In this case, we’re focusing on the GATES belt system, which doesn’t fundamentally differ in function from the chain variant. The biggest hurdle is integrating the gearbox into the frame – which has a major impact on the character of the bikeUnlike a traditional drivetrain with a cassette and a rear derailleur, all shifting is handled by a centralized gearbox integrated into the frame. So the question isn’t just: belt or chain? But rather: gearbox or rear derailleur? But what are the pros and cons of the respective systems?
A frequently cited drawback of gearboxes is the increased system weight, which can amount to around 1.5-2 kg depending on the setup compared to a conventional drivetrain. However, the World Cup is showing a different trend: many teams are intentionally mounting additional weights around the bottom bracket to improve ride dynamics. The low, centralized mass contributes to a planted, more stable bike – an advantage built into the very concept of gearboxes like Pinion’s. Instead of carrying a heavy cassette and a rear derailleur in the form of unsprung mass, the weight is shifted low and centrally into the frame – right where it causes the least disruption and can even bring advantages in terms of sheer riding performance.
In downhill racing, every line counts, every second makes a difference – and every pedal stroke involves risk. With a conventional drivetrain, you have to pedal to shift gears. And that’s risky, especially when you have to change into a different gear to prepare for the next section. Most of us clipped a pedal mid-stroke before, and the risk of flying over the bars is something we all want to minimise. Gearbox systems elegantly solve this issue, allowing you to shift while stationary, while riding at full speed, and, crucially, without having to spin the cranks at all. This opens up entirely new tactical options in DH racing: Riders no longer have to plan strategic pedal strokes during track walks just to shift gears in specific sections. Moreover, the new Pinion Smart.Shift gearbox allows shifting under load – something that wasn’t possible for a long time and posed a major issue. However, the electronically controlled gearbox waits for a moment of minimal pedal pressure to shift, which works well – though not quite as seamlessly as a SRAM Transmission derailleur, for example.”
Another major stumbling block of earlier gearbox systems was the sheer force required to shift gears. Since standard shifters couldn’t transmit this force efficiently, many setups relied on grip shifters – the kind most of us remember from kids bikes. Of course, this system makes it harder to hold your bars firmly on technical trails. Pinion overcame this issue with their Smart.Shift technology, allowing for electronic shifting with a standard-style shifter again.
A GATES belt combined with a Pinion Smart.Shift gearbox – as used by all four DH teams – can have up to 600% gear range. That’s more than any conventional 12-speed drivetrain. There’s no exposed derailleur that can snap off during a crash. No flimsy chainring that can bend when hitting a rock. That said, gearboxes aren’t flawless either. A heavy impact can damage the gearbox casing and even internal components, potentially rendering the entire system inoperable – whereas a rear derailleur can usually be fixed or replaced in a matter of minutes. Of course, crashes can still break components or tear the belt – something we’ve already experienced with eMTBs. Shifters – often designed specifically for these systems – aren’t always as robust as their conventional counterparts, and we’ve seen failures here as well. Moreover, sourcing spare parts and carrying out repairs on gearboxes is usually more complex and costly. This is where quality of implementation and detailed engineering make all the difference.
The Atherton A.200.G in detail and first test review
One of the biggest hurdles on the road to the World Cup was the technical implementation: who could even manage to develop a functioning bike with a GATES belt drive and gearbox in such a short time? The system requires a significant amount of space and has a major impact on the rear suspension design. All the more impressive, then, that the team around Atherton Racing took just three months to turn the initial idea into a rideable bike. The clear advantage: their own manufacturing technology – which also produces the commercial models – and a flexible, highly motivated development team.
Like all A-models, the Atherton A.200.G is built using additive manufacturing, where 3D-printed titanium lugs are bonded to carbon tubes. A particular challenge was the sheer size of the titanium lug that houses the Pinion Smart.Shift gearbox – no other Atherton bike features such a large part. Furthermore, the DW-Link rear suspension had to be redesigned from the ground up. The A.200.G now relies on a mid-high-pivot system instead of the classic 6-bar DW-Link of the A.200. Depending on the configuration, the Pinion gearbox can be run with 6, 9, or 12 gears.
During our visit to the DYFI Bike Park, we had the exclusive opportunity to take a few laps on one of the A.200.G prototypes and get a first-hand impression of the system. From the very first meters, the difference compared to conventional drivetrains was striking. The low center of gravity combined with the extremely light, nearly floating rear end noticeably changes the bike’s balance – and requires some adjustment. When riding through root carpets and rock gardens, you expect the usual reactive kick from the rear end – but this never comes. Instead, the rear end remains impressively composed, absorbs hits confidently, and maintains constant ground contact. The result is an exceptionally planted ride feel that inspires confidence, especially at higher speeds. But even in fast, dynamic corners, the system consistently plays to its strengths. The precise main frame combined with the composed rear end allows for clean line choices – whether in tight berms or wide off-camber sections. Big jumps and stylish airtime maneuvers are no problem either, though they do require slightly more input from the rider. Once in the air, the bike remains extremely stable and offers maximum control.
Shifting also takes some getting used to. The shifting action demands a bit more finger pressure than conventional drivetrains, though it’s not intrusive. Shifting under load is feasible, but not perfectly smooth. That said, the ability to shift without pedaling proves incredibly effective in real-world use: mid-berm, in technical rock sections, or in fast compressions, gear changes can be executed precisely and without delay. Practical, safe, and with growing familiarity, this quickly becomes second nature. The bike itself is eerily quiet. No metallic derailleur clatter, no chain slap – the only the sound you can hear are the tires biting into the ground, and the faint hum of the Pinion unit while shifting. Once you’ve experienced this kind of silence, traditional drivetrain systems almost feel intrusive.
For which type of MTBs does a gearbox drivetrain make sense?
Despite all the pros and cons, it’s essential to make a clear distinction: whether a belt-drive gearbox system makes sense strongly depends on its intended use. In downhill racing, its strengths come to bear almost uncompromisingly – optimally positioned weight and reduced unsprung mass, free gear selection without risky pedal strokes, and lower risk of mechanical failure.
Things look different when it comes to enduro and trail bikes. Here, it’s not just about downhill performance, but also about pedaling efficiency and the impact of added weight on climbs. The added weight of a centrally positioned gearbox can be more detrimental on extended rides or demanding climbs. Furthermore, trail and enduro bikes typically involve more consistent pedaling, thus requiring more frequent gear changes under load – and these shifts can sometimes be less smooth, since riders are reluctant to ease off the pedals uphill. Space inside the frame also becomes a more critical factor. Not every rear suspension system is suitable for gearbox integration. We’ve already encountered this issue with the integration of motors on e-mountainbikes: brands like Santa Cruz moved away from their well-known VPP layout to better integrate an electric motor into the frame. And today, no one wants a trail or enduro bike without a bottle cage – features like integrated storage compartments are virtually standard. All of these require space within the main frame triangle, which is already limited, especially in smaller frame sizes, and even more so with the addition of a gearbox.
In terms of suspension kinematics, a gearbox can enable more precise tuning of anti-rise and anti-squat because there’s just one sprocket and the values stay consistent. However, this can also be a downside in trail or enduro bike development, where anti-rise and anti-squat are often optimized for specific scenarios – uphill and downhill – and for corresponding sprocket positions. With a gearbox, this kind of fine-tuning is no longer possible.
There are also rising costs and the significantly more limited range of gearbox solutions to consider. A gearbox-specific frame platform requires uniform integration across all models derived from it. This drastically reduces the flexibility for offering more affordable spec variants, and spare part availability is currently still a challenge. On the other hand, the system truly shines in areas where frequent maintenance or fragile components are a disadvantage. No clogged derailleurs, no rusty drivetrains, no bent hangers – clear benefits for those who choose riding over wrenching. But is that enough to establish a foothold in the mainstream market?
The decisive question remains unanswered: will belt-driven gearbox drivetrains, starting from the Downhill World Cup, make their way onto trail and enduro bikes – much like the once-exotic high-pivot suspension design? The parallels are striking. Back then, just like now, the systems were dismissed as too heavy, too loud, or too complex. Today, high-pivot bikes are tearing through the woods even in lightweight trail configurations, because continuous development has resolved many of those early teething problems. So why not with a gearbox too?
Conclusions about gearbox drivetrains
The belt-driven gearbox drivetrain is more than just a passing trend – it offers clear advantages, especially in downhill applications. With centralized weight distribution, reduced unsprung mass, and intelligent shifting logic, the system presents tangible strengths. However, when it comes to trail and enduro bikes, it remains a matter of balance: high development costs, increased weight, and reduced design flexibility for manufacturers stand in contrast to gains in ride dynamics, durability, and serviceability. For these systems to become established, ongoing development is key – and that development is now gaining serious momentum.
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Words & Photos: Peter Walker
