ROTOR is entering the electronic drivetrain game with the UNO group, a simple two-piece system designed to shift everything from 10- to 13-speed setups. The pitch is straightforward: keep the parts count low, minimize weight, and let riders bring their own cassette—as long as it fits the spec.
What’s included in the system
The UNO wireless kit consists of a derailleur and a single shifter. The shifter runs on a coin-cell battery, while the derailleur houses a 600mAh battery that’s bolted directly to the body and is not user-replaceable. ROTOR hasn’t spelled out the charging method for the battery; given that it’s bolted onto the derailleur, riders will likely need to park their bike next to an outlet. The fixed battery arrangement is likely due in part to patent considerations.
Weighs less and has a higher-capacity battery
ROTOR lists the combined shifter-plus-derailleur weight at 453g, which undercuts Shimano and SRAM’s electronic offerings. For reference, a Shimano XTR Di2 shifter and derailleur weigh a combined 515.5g while the SRAM X0 Eagle Transmission bits weigh 520.2g.
On paper, UNO’s 600mAh derailleur battery nearly doubles the capacity of Shimano XTR Di2’s 305mAh pack. Whether that translates to double the ride time between charges will come down to efficiency. According to ROTOR, “the [shifter] and derailleur feature a motion-synchronized auto-start system” that should reduce battery drain while in transport or in storage. The fixed, non-user-replaceable battery does raise long-term service questions, though it likely helps ROTOR save weight and improves durability.
ROTOR says the system is capable of a 150ms/gear shifting speed, though the brand doesn’t clarify the test conditions for that number, which makes an apples-to-apples comparison to Shimano or SRAM difficult.
Compatibility and setup
ROTOR UNO will work with 10-, 11-, 12-, and 13-speed cassettes, and it’s rated for cassettes with cogs ranging from 10T up to 52T. Official guidance recommends using ROTOR’s own cassettes or the SunRace co-developed cassette “for the best performance and results,” though the company also states there are “no limitations” on other brands’ cassettes or sprocket configurations as long as they’re within spec.
Singletracks tested the non-electric ROTOR 13-speed groupset in 2020. That system utilized hydraulics rather than cables and saw limited adoption. SRAM currently offers a 13-speed drivetrain group, though it’s geared toward gravel bikes.
The ROTOR 13-speed 10–52T cassette weighs a claimed 331g, which is lighter than Shimano XTR (364.6g) and SRAM Eagle X0 (378.3g). As of press time, the ROTOR website shows their 12- and 13-speed cassettes are priced at 50% off, which makes them cheaper too.
An accompanying smartphone app lets you configure the derailleur for your specific cassette and align the derailleur’s indexing to your chosen range. The system is also set up to receive over-the-air firmware updates over time.
A gravel group is also being released based on the same derailleur as the ROTOR UNO mountain bike group, though with a modified pulley configuration. There’s a drop-bar specific shifter for the gravel system, and like the MTB system, it’s one-by only.
Pricing and availability for the ROTOR UNO shifter and derailleur were not available as of press time.
UNO’s minimalist hardware, broad cassette compatibility, and low weight could make it a compelling option for riders who want electronic shifting without a full ecosystem commitment. The fixed derailleur battery and unclear charging scheme are the big open questions, along with real-world battery life and shift speed under load. If ROTOR can deliver smooth shifts across 10- to 13-speed cassettes and keep pricing competitive, UNO could carve out a decent niche in the wireless drivetrain market.
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