Rotor Uno hydraulic shifting drivetrain examined

System designed to be lightweight, easy to maintain and operate

Parts Sea Otter Classic

2016 Sea Otter Classic

Buyers of this new drivetrain will certainly stand out from the crowd at their next coffee shop ride.

Buyers of this new drivetrain will certainly stand out from the crowd at their next coffee shop ride.

After first telling you about Rotor’s new hydraulic-actuated shifting system last summer, we have gotten our first up-close look at the drivetrain that was a six years in development. The first thing that jumps out is weight. While not yet independently verified, Rotor claims its oil-filled system comes in at just a shade over 1600 grams, or about 10 grams less than a cable-actuated SRAM Red set-up, and 400 grams lighter than Shimano’s Dura Ace Di2 electronic system.

This weight reduction, explained Rotor’s Chris Tarlton, comes via a mix of smart materials choices and the inherent make-up of the Uno system.

“On the materials side we’ve done a lot of CNC machining to the alloy and used carbon fiber where possible,” said Tarlton. “Then, of course, you are replacing cables and housing with lightweight tubes and hydraulic fluid. There are also no mechanisms in the shifters. Instead it’s all located at the derailleur. This too saves weight, and also results in a simpler system because the key parts are right where the shifting is actually happening.”

All shifting mechanisms are housed in the derailleurs, which is designed to speed shift speed and shed weight.

All shifting mechanisms are housed in the derailleurs, which is designed to speed shift speed and shed weight.

Tarlton claims that results in nearly zero lag time between shift input and the actual shift itself. And based on a very brief test ride on a trainer-mounted bike in the Rotor booth, we can say he’s spot on. Shifts up and down, front and rear, where quick and precise. In the real world, the system is being raced by some riders on the WorldTour Dimension Data squad as well as the Bigla women’s team, and Rotor says team feedback has been invaluable.

The system operates similarly to SRAM DoubleTap, where a short throw moves the derailleur down the cog or onto the small chainring, and a longer input moves the chain either up the cog or into the big chainring. You can set it to shift between one and four gears per lever input for the long throws.

Rotor also went to work on the cassette, creating a three-part steel-alloy combo that comes in at a claimed 149 grams in an 11-28. There is also a nifty disengagement feature where the flip of a small lever on the rear derailleur allows the cage to be moved independently, which makes wheel changes easier.

Shifting (and shift paddles) are very similar to SRAM's doubletap set-up.

Shifting (and shift paddles) are very similar to SRAM’s DoubleTap set-up.

The hydraulic hoses are a scant 3mm wide, which allows them to route through the same holes used by electronic shifting system wires. And of course because housing encases fluid not wires, tight routing bends have no impact on performance.

Not surprisingly, Rotor Uno is not aimed at the Ultegra crowd. A full groupset including hydraulic rim or disk brakes, but not cranks, retails for $2500. Systems come pre-bled and there is a 10-year leak-proof warranty, so no need to worry about doing bleeds yourself.

“This is definitely a premium product,” conceded Tarlton. “This is for the rider who has a custom made bike, or is really into the tech side of things and wants to be a little different on the coffee shop group ride. We also want to stress the reliability. There are no batteries to charge, no cables to stretch. Look at industries such as automotive and airplanes. All the key safety elements are run by hydraulics.”

The front derailleur's rear cage plate is specifically designed to work with ovalized Rotor Q Rings.

The front derailleur’s rear cage plate is specifically designed to work with ovalized Rotor Q Rings.

Rotor plans to make just 1500 of these made-in-Spain units this year. Anyone interested should contact Rotor USA directly.

“We’ll be doing VIP installs,” added Tarlton. “We want to know who is riding it, and treat each of those customers as a member of the Rotor family.”

A total of four strain gauges help deliver an array of information, including left/right power.

A total of four strain gauges help deliver an array of information, including left/right power.

And if you really want to fit in with the family, you’ll also want to pick up one of Rotor’s new 2INpower power meters, which measure right and left output, along with cadence, torque effectiveness, pedaling smoothness, and left/right balance. The system is run off a lithium battery with a claimed 250-hour run time. Four strain gauges keep track of your power output, and the system has a claimed weight of 645 grams for crank, spider, and spindle. Price is $1500.

For more information on both products visit rotorbike.com.

This article is part of RoadBikeReview’s coverage of the 2016 Sea Otter Classic in Monterey, California. For more from Sea Otter CLICK HERE.

Photo Thumbnails (click to enlarge)
About the author: Jason Sumner

An avid cyclist, Jason Sumner has been writing about two-wheeled pursuits of all kinds since 1999. He’s covered the Tour de France, the Olympic Games, and dozens of other international cycling events. He also likes to throw himself into the fray, penning first-person accounts of cycling adventures all over the globe. Sumner, who joined the RoadBikeReview.com / Mtbr.com staff in 2013, has also done extensive gear testing and is the author of the cycling guide book "75 Classic Rides: Colorado." When not writing or riding, the native Coloradoan can be found enjoying time with his wife Lisa and daughter Cora.


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