REVIEW: Rocky Mountain Dyname 4.0 Drive Unit

I looked at the drive for e-bikes from the Canadian Rocky Mountain brand called Dyname 4.0. It is a unique design solution of the drive for electric bikes.

Electrical system parameters

• nominal power: 250 W
• maximum power: 770 W
• torque: 108 Nm
• 4 levels of assistance: Ludicrous, Trail Plus, Trail and Eco
• the system is equipped with a torsion sensor
• maintenance-free engine type
• maximum speed of electrical assistance: 25 km/h ± 10%

Pros:

• design solution compared to competing manufacturers - it is a unique drive design where the crank converter is not driven
• the structural solution of the drive to the frame allows the use of high-quality geometry, so that the e-bike is very easy to control even when using a large-capacity battery
• stable mounting of the motor in the frame, so that the drive does not move in the frame - several-point fixed connections
• the advantage of long-term sustainable operation thanks to the possibility of replacing individual drive component
• the most stressed place on a bicycle is the center axis - here the motor is located separately and the classic center axis is used as in analog bikes
• individual components of the drive are serviceable - torsion sensor, transmission chain, bearings, motor
• the possibility of connecting an external 314 Wh battery + charging both batteries at the same time - overall you get an electric bike with a battery capacity of 1034 Wh or 794 Wh (when using the integrated battery 480 Wh)
• large clear display in the frame - easily visible even at night without dazzling the rider
• the possibility of individual adjustment of the engine performance curve without the need to use additional equipment - only using the wheel display
• the drive offers a torque of 108 Nm - in practice it behaves the same as riding an analog bike - there is no oversteer of the converter as with conventional drives - in the field it brings a positive effect in the exit, when the bike has better grip and there is a better dosing of the power of the drive to the wheel
• the drive can be controlled using the display even if the buttons on the left grip are damaged

Cons:

• service interval of 3000 km on the transmission chain
• the need to calibrate the torsion sensor (approx. once a month depending on the run-in and wear of the chain)
• more frequent chain lubrication compared to classic conventional drives