Gearboxes are suddenly all the rage in DH. So why haven’t they taken off for trail bikes?

It has been roughly one year since Gates announced its €100,000 reward for any elite-level racer who wins a Mountain Bike DH World Cup race on a Gates belt-driven bike. The prize money went uncollected in 2024.

However, Gates has extended the offer into the 2025 season, which will kick off in a few weeks. Several race teams are incorporating belt-driven gearboxes on their DH race bikes, making 2025 the year that Gates could pay out.

Teams such as Intense Factory Racing and Atherton Racing have ditched derailleurs for belt-driven gearboxes. Other teams, such as the newly formed Aon Racing, will be on gearbox-equipped Gamux DH bikes, while MS Racing will race Zerode, the belt-driven gearbox bike you’re most likely familiar with.

At least some World Cup teams see the potential advantage of a gearbox and are willing to re-engineer their bikes around it. This is no small feat, especially considering everything that goes into creating a World Cup-level DH rig. 

Despite the gearbox adoption on DH bikes, and the availability of MTB gearboxes going back more than a decade, the tech has seen minimal traction with trail bikes. But with modern trail bikes becoming more capable descenders, perhaps they also take advantage of gearboxes’ descending performance promises. 

Yet, they haven’t. But could that be changing in the near future? 

Why a gearbox?

Think of a gearbox like your vehicle’s transmission — a series of gears, internally housed and safe (hopefully) from the elements. Gearboxes are located at the bottom bracket as opposed to a traditional drivetrain with a cassette and derailleur at the bike’s rear. A gearbox has no derailleur, and in place of the cassette is a single rear sprocket ranging from 18–39 teeth.

According to the gearbox manufacturer, Pinion, this change from a traditional drivetrain gives the bike an advantage over typical 12-speed bikes. And, perhaps, this advantage is most noticeable on mountain biking’s fastest stage.

“The advantages of gearboxes in downhill riding are game-changing and obvious,” Dirk Menze, Head of Marketing and Design at Pinion, told Singletracks in an email. “Teams and riders are already openly acknowledging them: optimal weight distribution, a low center of gravity, and significantly improved rear suspension performance.”

Pinion introduced its P1.18 gearbox to the public in 2011. Mountain bike brands such as Nicolai, Endorfin, and Zerode were early adopters of the P1.18. Zerode leads the gearbox bike market and relies exclusively on Pinion’s technology. In time, it became clear that the 18 gears and 636% gear range the P1.18 gearbox offered were perhaps too many. This led to Pinion developing a 12-speed version, which ultimately evolved into today’s C1.12i.

All four World Cup race teams mentioned above have partnered with Pinion to equip their DH bikes with the C1.12i gearbox. In addition to Pinion gearboxes, these bikes run a Gates Belt Drive instead of a traditional chain. While Gates Corp has a long history stretching over 100 years, they have been working on mountain bike innovation since 2007.

And Gates sees some of the same advantages to gearboxes as Pinion does.

“Shifting weight from the rear wheel to the bike’s center enhances handling, giving riders

better control,” Chris Sugai, General Manager of Mobility at Gates Corp, told us. Sugai is also the founder of Niner Bikes.

In a time when DH racers are adding weights to the bottom bracket area of their bikes for improved performance, we can see the benefit of a gearbox. However, gearboxes also free your bike’s suspension from the additional weight of a cassette and derailleur, as well as limitations such as chain growth and pedal kickback.

Another point where Menze and Sugai agree is the reduced noise of a belt-driven gearbox, along with far less maintenance. “Belt-driven bikes also offer a nearly silent ride and unmatched durability, with our CDX Belts outperforming traditional chains in strength and reliability,” Sugai said.

But no gearboxes on trail bikes?

With all the wonderful descending benefits of belt-driven gearboxes, there surely are no downsides, right? Wrong. According to Gates and Pinion, gearbox adoption has a few notable hiccups. 

And these issues are the very things keeping gearboxes off of trail bikes.

The added weight is a typical first thought. But Menze at Pinion points out this mainly affects lightweight XC and trail bikes.

“In downhill riding, there is no disadvantage,” he explained. “In cross-country, the primary drawback is the added weight.” Depending on the drivetrain, a gearbox can weigh one to two pounds more. While some may not care about the weight penalty, or notice, it is present.

Menze and Sugai pointed out another disadvantage of gearbox adoption: Switching to a gearbox requires mountain bike brands to rethink and redesign their frames entirely. This is related to the reality that gearboxes are somewhat of a novelty in an industry that already demands high prices. And novelties tend to cost more. 

Novelty or not, Menze and Sugai think it is only a matter of time before more brands use gearboxes, not just on their DH bikes. It may just take some out-of-the-box thinking.

“The current momentum for gearbox drivetrains will, in the medium term, bring entirely new players into the market — ones that can break free from conventional constraints and embrace this disruptive technology,” Menze told us.

Sugai agrees, stressing that it’s only a matter of time until more brands build bikes with belt-driven gearboxes for trail bikes. Gates believes that once DH teams showcase the advantages of belt drive systems, the concept will make its way to enduro and trail bikes.

What about the bike brands?

It isn’t just “belt-driven gearbox guys” like Menze and Sugai who acknowledge the benefits. Companies like Transition Bikes echoed many of the same advantages a gearbox offers. 

“I think a huge advantage for some people would be the lower maintenance,” Sam Burkhardt, Product Director at Transition Bikes, told us via email. “There are a lot of people out there with beat-up drivetrains that are shifting terribly and chains that are super dirty and/or worn out. Those people could definitely benefit from a gearbox.”

But reduced maintenance alone isn’t likely enough for brands to make the switch. Despite DH racers’ clear advantages, Burkhardt doesn’t see any real potential for trickledown. Because gearboxes and belt drives have been in the DH category, this may actually keep some brands from going the gearbox route. In the end, DH may be too niche.

“DH race bikes are also a product category where sales volume potential and retail price aren’t the biggest concern,” Burkhardt said. “There isn’t that much risk for a brand that is supporting a race team to invest in something different for those athletes to use.”

Incorporating gearbox usage into a company like Transition would be no easy task. And doing it on a flagship model, like a trail bike, is a massive gamble.

Burkhardt explained that there are enough significant differences around the gearbox area of the frame to require starting over with the kinematic and layout-related side of the frame design. It would mean an entire redesign and layup of at least the front triangle. While there is potential for sharing a gearbox front triangle with a rear triangle and/or linkage parts from a non-gearbox version, there would still be incredible upfront costs.

And those high upfront costs would be difficult to justify for a niche user group.

So, does that mean we will never see a gearbox on a Transition trail bike? 

“I can’t comment on what we may or may not be working on,” Burkhardt said. “But we definitely keep an eye on all the options out there and test as much new stuff as we can.”