At this point in the technological history of mountain biking we currently have hydraulic disc and rim brakes, hydraulic fork lock outs, and hydraulic dropper seat posts, so why not hydraulic shifting? That seems to be what Acros is thinking as they are reincarnating Christophe Muthers’ 5-Rot hydraulic shifting system that was first debuted at Eurobike in 2006.

I remember seeing photos of the system, wondering how well it would work, but sadly, the concept never made it to production. Until now.

Acros has picked up the design and made a few necessary changes to make it broadly compatible with today’s mountain bike drivetrains. The first run of production will be extremely limited, as Acros is only planning to manufacture 250 complete sets world wide, which surprisingly are all ready starting to be pre-sold despite the nearly $2000 price tag here in the US.

Check out the A-GE system details, pricing, and whether or not you can find a set after the break!

While the mechanics of the system haven’t changed, Acros had to create some improved shifter mounts to ensure that the shifter position would offer enough adjustment regardless of how one would set up their controls. Also, now Acros offers the ability to integrate the shift lever with popular brake levers as well.

Shifting the A-GE system is accomplished by pushing the lever forward, which allows up to 3 shifts in either direction. Pushing the bottom of the shift lever changes the oil flow, which changes the shifting direction.

While it is common practice today for rear derailleurs to use a slanted parallelogram design, in the Acros system, both derailleurs utilize the design, which results in a very compact, yet stiff front derailleur. The rear derailleur will be offered in both long cage and mid cage versions for the first run of production. In addition to the cages, you can also change out the Raster Rod which provides shifting feedback, but also is available in 8, 9, and 10 speed versions.

In order to connect the hydraulic system, both derailleurs have two minuscule hydraulic lines attached which allow the flow of oil to move the derailleur. If you notice, there seems to be a lot of tiny connectors, which would make for a lot of separate parts, and you would be right considering there are an incredible 248 parts that make up the entire system! That’s not to say it’s not light though, and considering the fact that the shifter is only 65g, it’s not hard to believe that the A-GE system comes in at 150-175g lighter than it’s closest mechanical competition.

So why even bother with a hydraulic system in the first place? For starters, the A-GE system promises silky smooth shifting, which will stay that way. Without cables and housing to deteriorate over time, the shifting quality of the hydraulic system shouldn’t change. Keep in mind, that a shifting system will not experience the heat cycles like a disc brake would, so barring catastrophic failure the sealed system should remain at peak performance for a long period of time, if not indefinitely. Clearly, the price will keep the majority of the market from experiencing hydraulic shifting first hand, but like any good technology if it works there will undoubtedly be some trickle down to a more attainable price.