Roc D'Azur 2012: Cavalerie DH Gearbox Bike
Oct 12, 2012
For more than ten years now Cavalerie have been working on an alternative for the conventional shifter and mech. At Roc D'Azur this year they presented their range of gravity-ready bikes, fitted with internal gearboxes and carbon belt drives.
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 Their DH bike, the Falcon. Vital stats are: 200m travel, 63.5 degree HA, 9-speed effigear gearbox, carbon belt drive and sub-18kgs (39lbs). |
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| A Gates carbon belt drive transfers the power to the rear wheels - one of the big advantages of the belt drive is that, unlike a chain, it doesn't stretch so all the power is transferred to the rear wheel. One of the big challenges with belt drives is that they need to be under constant tension, so they have used a concentric pivot around the drivewheel to maintain a constant distance between the gearbox and rear sprocket. To further keep the tension on the belt there is a tensioner just after the rear sprocket, although Cavalerie admit that the version here is still a prototype and they are not yet happy with how it performs. With these pre-production bikes they are using a freehub on the rear wheel, but the finished bikes will come with a fixed rear hub as the freewheel slows down the pickup of the system and there is already a freewheel at the crank. |
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| While this may look like a twist shift, it's actually a very different system altogether - it's a sequential shifter. That means that you change one gear at a time - so to drop through the box you would make a series of rapid movements, rather than one, long twist. Effiegear explain that this keeps your wrist position more neutral at the shifter, rather than having to over-extend like you would on a long shift with a gripshift system. Like many other gearbox bikes, it uses a two cable system to operate the gears. |
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| Sitting next to the Falcon in the Cavaleire range is the 185mm Squirrel. It's got the same gearbox and belt drive, a 66 degree head angle and weighs in a less than 17kg (37.5lbs). |
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| The Squirrel shares nearly all of its features with its bigger brother, including suspension layout and how the gearbox works with the bike. The close-up shot should show you better how the concentric pivot works - the swingarm pivots either side of the gearbox and the sprocket sits outside all of this. |
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| While the shifter may look identical to the one on the Squirrel, this one is a more conventional twist shifter. |
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| This is what's going on inside here. One thing that Effigear have done that we haven't seen before is offer a range of gearing - there is a full nine-speed box on offer, which weighs in at 1.56kg, but there is also a slimmed down seven-speed box that drops the weight down to 1.39kg. This is possibly the first gearbox we have seen that doesn't have a weight penalty either - Effigear claim it weighs exactly the same as the equivalent Shimano Saint setup. It's also worth noting that the spline for the crank is a standard ISIS fitting. Right now you would need to use their specific cranks, but only because of the spacing, and because it is an established standard they are in talks with at least one crank manufacturer to produce aftermarket options for the system. |
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| This is probably a big deal. We see a lot of comments from people waiting to see a gearbox with a thumb shifter. Here you go. At this stage it is a prototype, but it's a working one...This means that customers will have the choice of how many gears they want and what shifter style they prefer. |
What do you think about the Cavalerie bikes? Does the combination of a trigger shifter, gearbox and belt drive at a sensible weight represent the future of mountain biking, or is it an overly complex solution to a problem that doesn't need solving? Have your say below.
www.effi-gear.com www.cavalerie-bikes.com www.ingeartec.com
Joking aside, this looks easier to replace than a chain and would fit in your pocket. I hope 'carbon belts' don't cost a fortune to replace...
