13-Speed Hydraulic MTB Drivetrain From Rotor at Eurobike

Rotor introduces a 13-speed hydraulically-actuated drivetrain for road and mountain bikes. All new derailleur, cassettes, hubs, and shifters.

With Rotor’s new 1×13-speed hydraulic shifting system, you may need to find some exercises to keep your left thumb from getting bored. Their cassette range is a massive 10-52t, providing smaller steps between gears with a cassette that feathers the scale 30% lighter than SRAM’s 12 speed Eagle XX1.

Video clip courtesy Rotor.

Derailleur details

Possibly the most striking element of Rotor’s latest drivetrain offering is the robust alloy derailleur. Indexing for the hydraulic shift system happens inside the derailleur, rather than up at the handlebar, and has been heavily tested in the mud with positive results. With no cables to clog or wear, overall maintenance is reportedly low. The mineral oil system uses a single 3mm hose for frictionless clicks, easy internal routing, and zero battery charges.

Hydraulic derailleur with shift-indexing and clutch inside

The long single-sided cage (the reverse “Lefty” of derailleur cages) is designed to accommodate the wide range of cassettes for road and mountain bikes within one derailleur model. The cage is held firm with an internal clutch that can be unlocked for easy wheel removal. Dialing in the pulley alignment is tool-free, using a small knob located on the outer parallelogram. Taking on all of the duties of precise shifting, adjustability, tension, and indexing, the derailleur resembles a futuristic tech-tank, weighing in at a reported 350 grams.

photo: Rotor

Cassette specs

Rotor will offer 13-speed cassettes in four different sizes, including 10-36t, 10-39t, 10-46t, and 10-52t. At the moment, these cassettes will require Rotor’s patent-packed disc hubs, available in 142mm x 12mm and 148 x 12 spacing. The 13-speed bits will not be available for a few months, and by shipping day there may be other hub options available. The upper body of the cassette is machined from one single block for lightweight precision, while the lower body is a solid piece of steel to ensure durability where riders need it most. The overall width of the 13-speed cassette is the same as a 12-speed and can use any standard 12-speed chain.

Proprietary 13-speed Rvolver hub, straight pull spokes, 6-bolt rotor mount

For riders who prefer to use their existing hubs, Rotor also offers a range of 12-speed cassettes that are compatible with standard 12-speed hubs. The new derailleur and shifter are designed to work with either 12 or 13-speed cassettes, and can easily switch between the two options by adjusting a limit screw, located near the tension spring on the derailleur. Additionally, the 12-speed cassettes provide a lighter-weight alternative for anyone using a SRAM of Shimano drivetrain.

Shifter info

Whether direct-mount or clamped to the bar, Rotor’s shifter design is decidedly minimal and lightweight, and for good reason. It doesn’t have much work to do. There is no indexing mechanism in the shifter, which makes for a light and fluid action. Riders can choose to run their shifting with a single trigger to shift up and down, or the classic double trigger. If you are into symmetry, the single trigger option would look well balanced with an under the bar dropper remote on your left side.

Shifter: Shot from the business end

Crankset and rings

Rotor offers a wide range of cranksets to complete the drivetrain, from their featherweight XC Kapic to the rock-ready R-Raptor. Oval and round chainring offerings are many, with a 1x-specific range from 26-40 teeth.


The 1×13 groupsets will be available in the first months of 2019, and with Rotor’s in-house manufacturing capabilities you can bet they will release the product the second it’s ready. Exact weights and a ride review will be available as soon as we get ahold of a test set. Pricing is not yet published for these latest bits, so stay tuned to Rotor’s media channels for more information.

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