While the current big deal is the launch of SRAM's Eagle - a massive 12 speed offering matched with the now commonplace single chainring up front (1x) - there is a would be successor in the shadows. The gearbox is not a new concept but has taken time (some say too much time) to be embraced by manufacturers and understood by customers.
A gearbox? Isn't that heavy, expensive, and complicated? Well, originally yes, but every year they have become lighter, more user-friendly and, in comparison to the prices for high end drivetrains, well... they're on par.
The big thing with a gearbox is where it sits and how it integrates to the frame design - it simply can't be an afterthought. The hard part? Frame and gearbox manufacturers need to co-design for it to work.
Sounds like a lot of hassle and negatives right? So what are the positives? The most immediate is reliability and durability. Less wear, less exposure to elements, and less likely to be damaged in a crash. Some say longer term it saves money over a traditional chain, cassette, and derailleur drivetrain. Then you have other benefits such as smooth, silent running and the ability to change gears without pedalling - imagine the situations that could be avoided with that as a benefit on its own...
All these pros and cons are amplified though when you add suspension into the mix. So, how does the gearbox argument stack up then? We spoke to Rob Metz, designer/director for the leader in gearbox bikes for the masses, Zerode, who seem to have cracked the code on combining all these elements together:
BR: Thanks for taking the time Rob. First up, let's talk about the Why?
Zerode: There are a lot of reasons why. I have been riding gearbox bikes for over 12 years and I know they make my mountain biking experience better. Derailleurs are fickle things, they need constant tuning, are exposed and prone to damage, they wear out quickly, and are expensive to replace, they are slow to change gears, you can't change without pedalling, they are noisy... the list just goes on. Surely the short falls of a derailleur are obvious to anyone that has ridden a mountain bike off road!
BR: So, what's better?
Zerode: Pretty much all of the issues I mentioned above can be addressed by using a gearbox. On top of that you get a fixed chain line so you can optimize the pedalling performance and a significant reduction in unsprung weight so your suspension works better. You have a gear that will do the job whether you are grinding up an epic backcountry single track or blasting down a high speed fire-road. Maintenance and tuning of gears are almost non-existent, sprocket and chain life are massively extended. You get that brand new drivetrain feeling every day, low ongoing cost, and gears change instantly. These are the reasons I started making my own gearbox bikes and why Zerode exists.
BR: So why are the big boys taking so long?
Zerode: The big boys are doing a good job of what they do; they make bikes, sell bikes, and make money. A gearbox is always going to be a little heavier than a mech set up. The media and the big boys would have you believe weight is more important than function. I'm in the other camp; I've been riding MTBs for 25 years and it is quite clear from my experience (and very, very basic physics) that a little extra weight makes very little difference - sometimes it will slow you down by a tiny amount and sometimes it will speed you up by a tiny amount. So, I choose to bring what I believe is the best product to market.
BR: What makes a good gearbox bike (not just a good gearbox)?
Zerode: A good gearbox bike isn't so different than a good mech bike except it doesn't have a derailleur. They should pedal well, suspension should work well, geometry should be in a ballpark that works, and they should take advantage of all of the good points that a gearbox offers over a derailleur, i.e. less unsprung weight, lighter, stronger rear wheels, etc. It's really very simple.
BR: What's keeping this system from replacing standard drivetrains? Cost?
Zerode: I think gearboxes will replace standard drive trains in a portion of the MTB market. In this part of the market time is the only factor. If you are an actual mountain biker that rides actual mountain bike trails - they are better, it's a no brainer.