Rocky Mountain Dyname 4.0
In-house RM motor on Altitude/Instinct Powerplay. 108Nm/700W peak at 85rpm. 18.5% lighter than Dyname 3.0. 350% rider amplification.
Rocky Mountain Dyname 4.0 is the Canadian brand's in-house full-power motor, fitted across the Altitude and Instinct Powerplay platforms and built in collaboration with Propulsion Powercycle in Québec. The headline figures are 108 Nm of claimed torque, 700 W claimed peak output, 250 W rated, 48 V nominal and a 3.0 kg motor mass. This is the fourth generation of the Powerplay drive, replacing the Dyname 3.0 with a unit that is 18.5% lighter while keeping the same 108 Nm figure. In the forum's long-running efficiency comparisons it sits at the top of the pile, with @Andy5 grouping it alongside Specialized and Avinox for best watt-hours-to-vertical-metre return.
The numbers. Rocky Mountain's published spec is 108 Nm and 700 W peak, with a torque curve designed to reach maximum power at an optimal cadence of 85 rpm . Independent dyno work has typically measured peak closer to 573 W at the rear wheel once drivetrain and transfer-chain losses are accounted for, which is the honest figure to bring to a cross-brand comparison. There is a separate region-restricted profile referenced by Rocky Mountain that pushes the unit to a 1000 W ceiling, and @DylanJM flags exactly that number when correcting comparison tables. Rider amplification is quoted at up to 350% , and unlike most rivals there is no over-the-air firmware path: updates run through a dealer.
Character and feel. The Dyname's signature is a torque sensor that reads chain tension directly via a sprung pulley, which translates on trail to an unusually direct feel. Testers describe instantaneous power delivery that is more natural than rivals, with the torque sensor effectively invisible to the rider, although the system does cut power off faster than Bosch when you stop pedalling . Noise is a strong point: the 4.0 is one of the quietest eMTBs on the market, with a lower-frequency tone thanks to the motor operating at lower RPM . Drag with the motor off is low because the upper chain slider has been removed to reduce mechanical noise and minimise pedalling drag . In Trail and Trail Plus the modulation is the best argument for the motor; Ludicrous (Boost) is where you feel the full 108 Nm shove on a steep pinch.
Compatibility and ecosystem. The internal battery is 720 Wh, with a 314 Wh Overtime range extender taking total capacity to 1034 Wh. The four assistance modes are Ludicrous, Trail Plus, Trail and Eco , controlled by a bar remote and the top-tube Jumbotron display. Notably, Rocky Mountain forgoes any smartphone connectivity and puts every setting, including support-level personalisation, directly into the bike . The bottom bracket is a conventional BB92 sitting separate from the motor, with RaceFace cranks on either a 149 x 30 mm DH or 156 x 24 mm spindle , and chainline is set high to suit the mid-high pivot kinematics. Wheel support is 29in front and rear across the current range.
Reliability and known issues. The trade-off for the chain-tension torque sensor is maintenance. @Bad Mechanic is explicit: the transfer chain and motor sprocket o-rings need frequent replacement, and the correct lubricant is 20-weight way oil (Vacuoline 1409), not grease. Owners also need to recalibrate the torsion sensor roughly monthly depending on chain wear. Loam Wolf's long-term test logged occasional calibration loss that caused the motor to drive the rear wheel without pedal input, resolved via the Jumbotron, and a rarer clutch-bearing slip under hard pedalling after high mileage. Error-code communication failures have appeared on press fleet bikes but are not widespread in owner reports.
Bikes you'll find it on. The motor is exclusive to Rocky Mountain. The enduro flagship is the Rocky Mountain Altitude Powerplay 2025 at 170/160 mm with the Ride-4 chip and 10 mm adjustable chainstays; the trail option is the Rocky Mountain Instinct Powerplay 2025 at 150/140 mm, which uses the same Dyname 4.0 tune but with a softer Size Specific shock curve. The Rocky Mountain Altitude Powerplay 2024 alloy 30 Coil remains the budget entry, and the Rocky Mountain Instinct Powerplay 2024 carries the same 720 Wh pack and Overtime compatibility. @Account Deleted notes the Altitude is rated for 150 kg total system weight, useful context for heavier riders on long descents.
Verdict. The Dyname 4.0 suits riders who want the most direct torque-sensor feel on the market with 108 Nm in reserve, and accept a transfer-chain maintenance routine that other systems do not ask for. The genuine trade-off is the closed ecosystem: no app, no OTA firmware, and servicing depth depends on a competent Rocky Mountain dealer. Current Rocky Mountain flagship motor, launched 25 October 2021, still the only drive unit Rocky Mountain ships in 2026 and no announced replacement.
