Gearbox mountain bikes: mad science or the way forward?

The derailleur's days may not be numbered just yet, but this is a technology worth watching

The derailleur system has been around a long time. But there is another way – the gearbox.


Enclosed from the elements, components wear more slowly. But gearboxes are expensive and heavy, with that weight centred in one place. Hub gears, which have found a niche on city bikes, are no good for mountain bikes as their weight is concentrated on the rear wheel, which would play havoc with a full-suspension machine.

But Pinion, in conjunction with Nicolai, and Effiigear have been developing gearboxes that sit within the frame, with their weight centralised. The resulting lighter back end means more responsive suspension and enables the rear wheel to be undished, so stronger. A consistent chainline adds durability and there’s no derailleur to hang down and get beaten about on rocks, stumps and so on.

Several of our testers have tried Nicolai’s gearbox-equipped Ion, and found the system works reliably. But there are drawbacks – it results in a heavy bike, shifter ergonomics are poor compared with modern triggers and you can’t shift when putting the power down. It’s possible to work around these factors by adjusting your pedalling/shifting attitude, but it feels highly unnatural at first. Every gearbox bike we’ve tried has also felt more draggy than a regular MTB, because of the extra weight – something that’s disheartening if you have to pedal uphill.

On the plus side though, suspension performance is seriously impressive, feeling buttery smooth over pretty much every kind of obstacle that might cross your path. It’s easy to see how gearbox MTBs could appeal in environments where long, gnarly, rock-infested descents outnumber occasions when pedalling is necessary.

To secure mass appeal then, gearbox technology needs to address issues around weight, price, user-friendliness – and also the mounting system, which is in no way compatible with standard frames. But it remains a seriously interesting strand of bike development that we’ll certainly be keeping our eyes on.

Gearboxes on mtbs – are they the future?

What do you think? Let us know in the comments below…