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Acros AG-E brings hydraulic shifting to mountain bikes


April 20, 2011

The rear derailleur and shifter for the new AG-E hydraulic shifting system for mountain bikes (Photos courtesy Acros)

The rear derailleur and shifter for the new AG-E hydraulic shifting system for mountain bikes (Photos courtesy Acros)

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There was a time not all that long ago, when hydraulic brakes on mountain bikes were viewed as super-high-end equipment for the elite few. Now, virtually all bikes over the mid-range price point have them. At last weekend's Sea Otter mountain biking trade show in Monterey, a new product was unveiled that could lead to the same thing happening with gear-shifting, as German component-maker Acros presented its A-GE hydraulic shifting system to the world.

A-GE is a tweaked-up version of the 5 Rot system invented by Christoph Muthers, which he brought to the Eurobike trade show in 2006. While his original system never took off commercially, Acros brought him into its R&D; team, to further develop the product using the company's resources.

The system's front and rear shifters each consist of a single push-activated thumb paddle, which shifts the bike to a higher or lower gear depending on whether the user applies thumb pressure at an upward or downward angle. Two sealed hoses run from a cylinder in each shifter to a slave cylinder in the respective AG-E derailleur, carrying mineral oil that activates it to move the chain the desired number of clicks, in the desired direction.

Gear changes of up to three cogs are possible with one push, and the system will work with 8, 9 or 10-speed cassettes.

Acros claims that AG-E has much less friction than traditional mechanical setups, that incorporate steel cables sliding against the inside of housings, and stiffer return springs in the derailleurs. Because the whole thing is sealed and doesn't use cables that stretch over time, adjustments should also be relatively few and far between – as long as air doesn't get into the lines. When it does need attention, as is the case with hydraulic brakes, it will presumably not be particularly user-serviceable.

Perhaps surprisingly, the total 248-part system is said to weigh 175 grams less than the popular Shimano XTR mechanical system, and 175 less than SRAM's XX. This is said to be due mainly to the absence of steel cables and steel-reinforced housings. Much as AG-E may lighten the bike it's mounted on, however, it will also lighten the rider's wallet – the 250 individual systems that are slated to be available as of mid-May should sell for about EUR 1,599 (US$2,320), with US prices still to be announced.

Via BikeRadar and Pinkbike

About the Author
Ben Coxworth An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away. All articles by Ben Coxworth

Love those things you can\'t fix yourself. Especially at $2300 a pop. At 10,000 feet in Rockies and a line pops loose??

faceless minion


Now let Rohloff upgrade their hub with something like this and the world will be even better.


Faceless hit it dead center. Not worth it to me to pay over two large for a bike part that I can\'t even try to fix. Yet another example of a company trying to make something only they can service.

Kudos to Acros for a technological marvel. Now make it right.


Hydraulic gearchange? If only we had had it for the Morris Nomad -

Stuart Saunders

Sounds like a solution in search of a problem. Notice it doesn\'t really solve any problems with the traditional shifter. What I want is an electric servo based shifter that automatically shifts the gears for me based on my speed. It could be powered by a bottom bracket generator/sensor so it would beep at you if you needed to pedal for shifting to happen. No need for return springs so juice would not be used to hold the derailleur in position. It could also be adapted to a hub gear system with everything at the rear axle. So now that I\'ve ranted, has anybody seen anything like this?


If I were going to abandon the traditional cables, I think I would prefer an electronic system (there are both commute bike and race bike versions) to an hydraulic system.


Derailleurs are on the way out. checkout www.zerode.co.nz and see what the future of Mtb design is. The gearbox is the way forward for sure.

Chris Martin

I don\'t think this is a solution in search of a problem. Cable shifting is inherently unreliable due to cable stretch, wear and ingress of contamination. Hydraulic system makes a lot of sense. The weight saving is a huge bonus.

Does anyone remember the shift from Vee brakes to discs? There was a lot of resistance to hydraulic brakes; similar quotes of what if the line pops? The industry temporarily championed the cable discs until people became comfortable with hydraulics and embraced their superiority.

The user serviceability comment is a presumption; the author clearly hasn\'t bled his hydraulic brakes; I am sure it will be no different.

My main comment is that running separate inlet and return hose is the largest advantage. I\'d rather see a dual wall hose with inlet fluid running in the inner sleeve and the return fluid running on the outside or run them in parallel but put them inside a single sheathing. The price is pretty prohibitive at the moment but once it becomes more competitive, I\'d love to get a set!

Michał Klimek

I agree with facebook user, take a look at pinion bikes as well for another very tidy gearbox design.

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