Video: Acros Hydraulic Shifting In Action

Acros was on hand at PressCamp to show off their new A-GE hydraulic shifting drivetrain setup. The system works via two fluid filled hoses running between each shifter and the respective derailleur.

Based in Stuttgart, Germany, Acros’ factory has 46 CNC milling machines shared with their bearing company, which is where their bearing expertise comes from. Those bearings are incorporated into the shifters and derailleurs, and almost every part is machined in house. That’s a big part of why the system retails for $2,000 USD, but it’s also why it’s so light and so smooth.

The video above shows how it works, and more pics after the break fill in the story…

acros age a-ge hydraulic shifters for mountain bikes

The shifters work via a rotating thumb lever. Press the center of it and it pushes straight down to shift one way. Push the bottom of the thumb paddle and it rotates the paddle slightly to close one chamber and push fluid through a differnt hose which moves the derailleur in the other direction.

The benefits of this design are that you can switch from High-Normal to Low-Normal (ie. which button push shifts up or down) simply by swapping the hoses at either end of the system. You can also swap hoses from left to right to set up your front or rear shifting on whichever side you’d like.

Acros claims this system is 175g than XTR and 150g lighter than XX. Some of the weight savings comes from the shifters using a single lever for both up- and downshifts, and that it has no springs or mechanical parts inside.

acros age a-ge hydraulic shifters for mountain bikes

Just thinking out loud here, but the miniaturization of such seemingly complex hydraulic movements suggests that making a road shifting system can’t be too far behind, and that incorporating a hydraulic braking system into a road shifter/lever should also be very possible…perhaps the real delay is simply making sure there are enough disc-compatible road frames in the pipeline.

acros age hydraulic rear derailleur for mountain bike shifting

The shifting action is very smooth and light, and you can shift up to three gears at a time with a single push.

Because the hydraulic lines are so thin – about half the diameter of brake lines – they’re light, and they don’t require much fluid to move the derailleurs, which means there’s not much going on inside them. Translation: not much to go wrong, and little opportunity for contamination or air to effect performance. That’s the claim, anyway.

acros age a-ge hydraulic rear derailleur for mountain bikes

Another benefit is that the system can easily be used with 8-, 9- or 10-speed drivetrains by swapping out a single part. Why you’d want to run a $2,000 shifting system with anything but 10 speed is beyond us, but, hey, the option’s there.

acros age a-ge hydraulic front derailleur for mountain bikes

Like the rear, the front derailleur works with multiple gearing options: double or triple. The movement of both derailleurs is trapezoidal, not just linear, so the derailleur follows the chain line, which reduces chain tension in the rear and in the front it allows for a more compact design (less weight).

Every piece is CNC made in Germany, so it takes a while to manufacture. The first 250 sets are ready to ship now, the second batch of 1000 are queued up. At the moment, you’ll have to order direct if you want it in the U.S., but their working on distribution here. More thinking out loud, but it seems they could find a way to mass produce some of the pieces (cages, clamps, etc.) with forged or carbon parts and keep the weight similar or less while cutting costs and production time…which would go a long way into moving this system into the mainstream.

Comments

Joshua Murdock - 06/27/11 - 12:11am

This is awesome. I’d love to demo this.

marc basiliere - 06/27/11 - 8:05am

Low normal for 10s! Thank goodness someone is listening to us (all three of us).

marc

Gillis - 06/27/11 - 9:20pm

So I am curious what happens if/when you do break a line. I doubt there are springs on there so does the derailleur stay put on whatever gear you’re in or will it jump around?

Bad Bender - 06/27/11 - 9:24pm

From what I hear, if you break a line the derailleur stays in place. And you can move it to whatever gear you want to pedal home, since it’s the derailleur that is indexed, not the shift lever. This is awesome! I love it when a small(er) company innovates.

Henry Chong - 06/28/11 - 1:47pm

Great idea. Don’t like the look of double cables. If they can invent a sleeve around them that allow for splitting at the ends (sort of like an electric wire housing) then the look will be more sano.

richard - 06/29/11 - 6:46pm

This is the future! forget the elictric stuff that will run out i would like to see sram make one!!!!! this is really cool!!!!

jimmythefly - 07/03/11 - 10:46pm

Really cool stuff here. It makes so much sense no cable drag, no cable stretch, no issues with bending housing around tight corners, etc. Its’ build from so many individual pieces, but in theory that means if you break something you could replace just that part, not an entire derailleur for example.

If the indexing is in the derailleurs, then that also means it should be fairly straightforward to plumb in in-line secondary shifters.

This is certainly different from braking systems in terms of line pressure and master and slave cylinder sizing, so I’m not sure your theory is correct. Or rather, I think this type of system has little to do with road hydraulic discs, BUT I think you’re right that road hydraulic discs are near. Shimano doesn’t have to do much to the dual-control mountain levers to make them road levers, and with electronic shifting it would be even easier, as you don’t have any of the shifter mechanism to worry about.

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