Gearbox transmissions have been designed for use on mountain bikes for years now, but they have yet to catch on in the industry at large. They offer numerous advantages over a standard drivetrain, including higher durability leading to a much longer life due to the enclosed design, the ability to shift when not pedaling, better chain retention, and the opportunity to run a belt drive with a geared system. The latest units are also 12-speed systems, with a massive gear range.
The downsides include being significantly heavier than a standard drivetrain, and having more drag while pedaling from all the gears that are constantly engaged.
Still, many of us are sick and tired of tearing derailleurs off, replacing worn out parts, and dropping or breaking chains. The gearbox could be a great solution to many common drivetrain problems.
See Also: “Video: Are Gearbox Mountain Bikes Any Good?“
As I cruised the Eurobike expo in Germany, it was apparent that many smaller European brands are much more open to the idea of gearboxes than American brands, as I spotted them spec’ed on several mountain bikes. While it’s possible that the wet climate in places like the UK helps the popularity of gearboxes, I noticed them spec’ed on several display bikes kitted with full bikepacking bags and designed for that use–obviously playing on the durability and relative simplicity of the system.
Here are 8 gearbox-equipped mountain bikes I spotted at Eurobike 2016, organized in alphabetical order. Be sure to click through to check out all of them… number 8 is one of the coolest!
Bergwerk Murunatan
This steel hardtail sports a Pinion gearbox with a belt drive system and a classic singlespeed dropout tensioner. A RockShox fork handles suspension duties up front, with Shimano XT spec’ed for the brakes.
Looks like a good idea to me. I think it’s (gearbox) similar to Alfine internal hub but with benefit of weight being transferred from rear wheel to the center of the bike.
Can only imagine how much more these systems cost relative to chain / derailleur types.
Like the idea, and maybe on an adventure bike, DH, or even an enduro rig the weight penalty is acceptable. Any idea what the weight penalty actually is?
I agree with stumpyfsr. I like the fact that the drivetrain weight will be transferred to the b/b and help with the center of gravity. It makes the more whippy, so to speak. However, what do these thing run for? I’ll bet they ain’t cheap. So the question is: are they really worth the extra weight? Are they actually easier and more maintenance free than a regular shifter set-up? What happens if it breaks? Do bike shops have the tools needed to fix one of these gearboxes? Just some questions to consider. I’m sticking with a normal set-up until internal gearboxes become more common. Then we’ll see if they are worth it….
Back in the days of 3x drivetrains with their less than reliable shifting on the front chainrings, a gearbox drivetrain seemed like a good idea. Now, with modern wide-range 1x drivetrains like the Sram Eagle, gearbox drivetrains are solving a problem I just don’t have anymore. The fact that they weigh more, cost more, and are likely to be difficult to repair makes them even less favorable.
If and when they get the balance right – low enough weight, reasonable cost, etc, then these will become real game-changers. The advantages for the average rider are not there yet. But in certain applications, they might make sense. From my understanding, the units are fully sealed, and there’s little to no maintenance required for thousands of miles. So for someone doing a long bike-packing trip one of these gearboxes might make sense. If you price out the cost of an Eagle drivetrain, along with all the chains and cassettes you’ll need over the course of a few years, the additional upfront cost of a gearbox might start to seem less onerous.