Hydraulic Mountain Bike Shifters Coming to Market

Hydraulic shifters from Acros uses master cylinders and hydraulic fluid instead of cables. Photo: Jim Merithew/Wired.com

We saw a lot of compelling bike gear at Sea Otter earlier this month. But the one innovation that sticks out more than any other is this hydraulic-shifting setup from German component maker Acros.
Called A-GE, the mountain-bike system is the brainchild of engineer Christoph Muthers, who debuted the technology five years ago but was never able to bring it to market. Muthers now works for Acros, and the company has put his design into production, with availability set for late spring or early summer.
Typical shifting setups use cables and return springs to move the derailleurs back and forth across the gears. The A-GE design houses tiny master cylinders in the shifter bodies (the parts that attach to the bars). As the rider depresses the shifter paddles, pistons push mineral oil through two tiny hoses connected to the derailleurs. A straight push on the paddle will move the derailleur in one direction, while a minor twist before pushing will move it in the other.
Unlike traditional setups, which can get harder to shift the higher you go, the hydraulic system offers the same resistance for every shift, because there are no springs and cables getting progressively tighter with each shift. And because the design doesn’t require much of the larger hardware of a traditional mechanical setup, Muthers claims that an entire A-GE package—shifters, derailleurs, hoses, and oil—weighs 175 grams less than Shimano’s top XTR offering.

There's a tiny master cylinder inside each shifter mounted on the handlebars. Photo: Jim Merithew/Wired.com

The demo setup we played with at Sea Otter felt light, responsive, and ergonomically dialed in. The rear derailleur could shift up to three gears at a time in each direction on the demo’s 10-speed cog. Muthers says it can easily be indexed for eight- or nine-speed cogs by switching a rod inside the rear derailleur, though this would require a bleed of the fully sealed system. If you know what that means, maybe you could try it on your own. (Muthers says it’s easier than doing the same operation on hydraulic brakes.) Otherwise, it’s something for your bike shop.
Of course, that’s assuming you’re one of the early adopters willing to pay for all this. Muthers says Acros would like to offer A-GE for under $2,000 in the United States. But considering the 1,599-euro [$2,333] price tag in Europe, he admits that might be tough.

 http://www.wired.com/gadgetlab/2011/04/hydraulic-bike-shifters/