It’s not often that we get to try something genuinely new. The bikes we review are most often evolutions of existing designs, and most of the componentry we test aims to be lighter, stiffer, or cheaper than its predecessors, but it’s rarely fundamentally different. When we first caught wind that Rotor was planning to enter the groupset market we weren’t sure what to make of it. The market is dominated by Shimano and SRAM, with Campagnolo bringing up the rear. Rotor’s UNO group is fundamentally different, in that it is hydraulically actuated. This isn’t completely uncharted territory, however. The German company Acros already makes a hydraulic mountain group.
Who, what, where and why?
On the face of it, introducing hydraulics to shifting might seem like needless complexity. Cable shifting does, after all, work quite well, and for those that don’t want to maintain a cable system, electronic shifting offers fit-and-forget adjustment and less onerous installation requirements. (Electrical wires don’t mind going round tight bends.)
Rotor product manager Lars Janssen says the UNO groupset combines the best features of mechanical and electronic systems. It’s designed to offer a degree of mechanical involvement, low weight, low maintenance, easy cable and hose routing, and to be a natural match for disc brakes.
By moving the indexing mechanism to the derailleurs, UNO aims to ensure consistently accurate shifting. At the lever end, all you’re really doing is operating a hydraulic switch, meaning that the shift quality isn’t reliant on the hydraulics for its accuracy. As a result, Rotor anticipates extremely long service intervals – you’ll likely need to bleed the system after shortening hoses, but once set up it should work properly for years without intervention. In a similar vein, the braking system uses a non-water absorbing fluid (Magura Royal Blood), which reduces the need for frequent bleeding.
Rotor describes the UNO groupset as “its baby”, one its been pregnant with for six years. (This is almost a direct quote.) Final prototypes have been on the road with sponsored teams since November and Rotor has incorporated their feedback into the final product. The company is finally ready to give birth…
Details, details, details
For a complete hydraulic disc groupset excluding cranks, Rotor claims that UNO weighs just 1604g. According to its figures, this represents a saving of 10g over the equivalent SRAM Red 22 setup, 99g over eTAP, and 417g over Shimano Dura Ace Di2. Read on for details of UNO’s individual components.
What about cranks?
Pricing and availability
First ride impressions
You can read more at BikeRadar.com