EB13: Prototype Road Bike Acros A-GE RDA Hydraulic Shifters, Derailleurs w/ Formula RR1 Brakes
A few years back, Acros unveiled their A-GE MT hydraulic mountain bike shifter and derailleur system. Check it out in action here. Now, they’re showing a prototype road bike version called A-GE RDA paired with Formula’s RR1 disc brakes.
The levers and derailleurs are a blend of machined metals and miniscule hydraulic lines and pistons. It’s a closed system that simply uses fluid to push a derailleur one way or another. While the folks in the booth didn’t have any pricing, weight or launch information, saying it was only a prototype, it’s already printed into their 2014 catalog, so it may not be that far off.
Close up pics showing the lever movement, derailleurs and more below…
The rear derailleur looks very similar to the mountain bike version. Most of the parts used to make the group are machined in-house at Acros.
A small piston between the arms pushes or pulls depending on which way the fluid is coming in or out.
Once you’ve got the high and low limit screws set, you simply use the adjustment screw (threaded into the gold bit) to align the pulley wheel with the cogs. Once that’s aligned, they said it should shift perfectly from top to bottom.
This road front derailleur is a drastically simplified version of the mountain bike one. That one had a parallelogram that raised and lowered the cage like normal. This one’s front piston simply pushes it straight in and out.
It’s hard to see, but pushing the entire brake lever assembly inward (like you would a Shimano lever) pushes a small piston into the tank and forces fluid through one of the hoses.
Like the mountain bike group, you could likely change the direction of the shift for each movement by simply flipping the hoses’ mounting points at one end of the system.
Shifting the other way is handled by a simply twist of this lever.
The shifting system is completely contained on the brake lever, leaving Formula’s master cylinder and hoods unchanged.
For more on the RR1, check our coverage on Formula’s latest here.