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.

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