ROCKY MOUNTAIN ALTITUDE POWERPLAY
C90 RALLY EDITION REVIEW
Words by Drew Rohde | Photos by Dusten Ryen
Over the last few months we’ve passed the Rocky Mountain Altitude Powerplay C90 Rally Edition around to our testers. This was a bike we were really hoping would have arrived in time for our 2021 eMTB Shootout but shipping and COVID-19 delays had the bike show up just days after we returned from our trip. With countless hours on many of the latest and greatest bikes, we were eager to see where the Altitude Powerplay would stack up. Packing 160/150mm of travel front and rear and Rocky Mountain Bike’s own Dyname 3.0 Class 1 eMTB drive unit, it is certainly a unique machine with plenty of style and features for riders looking to get something a bit different.
The Altitude Powerplay is Rocky Mountain’s aggressive trail to borderline enduro offering, loosely based around the well-established analog Altitude. Of course some redesigns are necessary to account for Rocky Mountain’s powerful Dyname 3.0 motor. The system puts out up to 108Nm of torque and 250w of power backed by a 672Wh battery. Available in the Altitude Powerplay range are both alloy and carbon frame options, all rolling on 27.5” wheels with Maxxis Wide Trail tires.
THE E: When it came to designing the Altitude Powerplay line, the engineers at Rocky Mountain refused to allow the motor to dictate the frame, instead opting to ensure the suspension pivot points and geometry were as they desired. They then created the motor to accommodate these key points. This motor is a separate entity from what is effectively a “standard” mountain bike drivetrain, with the chain routed around a drive pulley on the motor and the frame being equipped with a regular BB89.5 Press Fit bottom bracket that accepts a normal crank with spindle. This is different in that the drive unit isn’t part of the cranks/BB and according to Rocky, offers benefits from reduced creaking to easier service.
The Dyname system meters the power delivered to the rear wheel via a magnetic field sensor which measures the chain position 1,000 times per second. This allows the motor to match the input stroke and reduce the lag that can sometimes be prevalent in some eMTB systems both when applying the power and when letting off. Something our testers noticed about Rocky Mountain’s eBikes is the instant engagement and disengagement while pedaling.
Rocky designed this motor to offer the peak 770W power at around 85RPM pedaling cadence, which they believe to offer the most natural feeling assistance. This power output is class-leading and it is definitely noticeable out on the trail. To help the Dyname 3.0 slide under the radar while passing your buddies on the climb, Rocky Mountain has designed the Dyname motor spins at 1,200 RPMs, roughly 25% the speed of many competitors. Rocky claims this reduces the “whir” when pedaling, which it does, however the system does have its own unique sound, one we feel may be a bit lower pitch and quieter.
The Li-ion battery unit is fully integrated into the downtube of the frame, boasting a 672Wh capacity and running on 48V. This enables the battery to reach full charging capacity in just under 4 hours, and can hit 80% capacity in just over 2 if the ride can’t wait. Rocky claims the battery life will support a 102kg rider for up to 2,000m of climbing, in part thanks to the increased efficiency of the 48V system opposed to a 36V. This can be boosted further by the addition of Rocky’s 330Wh Overtime pack external battery, which bolts on to the top of the downtube just above the motor and takes the full capacity to over 1000Wh.
Mounted to the bars is the iWoc TRIO V3 remote, which has three buttons to control the system. On/off; the power-assist selection; and activate the walk function for easy walking with the bike. The remote features an array of LED’s to indicate both the mode selected and the battery life remaining. There are three standard modes setup for the Altitude Powerplay: ECO, Trail, and Ludicrous mode for the maximum levels of assistance to climb the steepest of trails.
Further control of the Powerplay drive unit can be performed on a smartphone or tablet using the Ebikemotion app, offering the customization of each mode to fine tune to your preferences. Rocky mountain are so confident in the performance and longevity of their Powerplay system that they are now offering a 36-month warranty on all electrical components, which can be applied retroactively to any existing Powerplay equipped bikes already purchased. The battery carries a 2-year warranty, and the drive unit pulleys and pinions are backed for one year.
THE BIKE: We were sent the Altitude Powerplay Carbon 90 Rally Edition to test, which is based around a Carbon Fiber frame created using Rocky’s SMOOTHWALL Carbon manufacturing process. This process utilizes solid internal molds opposed to the conventional inflatable bladder, which eliminates the wrinkling on the internal walls of the carbon and removes excess resin in the process. The carbon layup is then tailored to each specific area of the frame to obtain the desired level of stiffness and impact resistance with the least weight. The 150mm travel rear end is controlled by Rocky’s Smoothlink four bar suspension system, which allows them to carry over the ride feel from their non-powered bikes to the Powerplay range. Each of the pivot points in this Smoothlink system spin on fully sealed cartridge bearings.
The rear shock receives size-specific tuning, which helps to ensure riders are given the same ride feel regardless of their height and weight, thanks to a specific tune for each frame size. In true Rocky Mountain style, the Altitude Powerplay’s characteristics are tunable with their Ride-9 chip located on the bottom mount of the shock. This makes for a complicated geometry table, but offers a full degree of head angle change which is accompanied by a 14mm change in bottom bracket height. In addition to geometry modification, the progression levels of the suspension are tuneable to tailor the feel to rider preferences and the trail, requiring only a pair of Allen keys to do so. Cable routing is an all-internal affair, and the lower two ISCG-05 tabs are in place to add a bash guard below the chainring if desired. The carbon frame is sculpted below the shock to allow for a bottle to be squeezed within the front triangle when used without the Overtime battery.
The Altitude Powerplay is available in sizes S-XL, with geometry that is decidedly on the nimble, fun-loving end of the spectrum. Seat tube lengths span from 419mm-521mm; reaches from 413mm-484mm; and stack heights from 579mm-623mm. Common to the range of sizes in the neutral geometry position are a head angle that sits at 65.6 degrees; a reasonably relaxed effective seat angle of 74.6 degrees; a compact 426mm rear end length; and a bottom bracket that sits 7mm below the axles. The size Large tested sports a 458mm reach and 610mm stack, which combine to give a relatively compact cockpit for a Large frame in 2021, with a tight 1,205mm wheelbase to match.
THE BUILDS: Rocky Mountain offers the Altitude Powerplay in five different guises. There are three spec levels for the alloy frame from the $5,219 Alloy 30 through to the $6,799 Alloy 70; and two spec levels in the carbon: the $8,599 Carbon 70 and the $9,399 Carbon 90 Rally Edition tested. This Carbon 90 Rally Edition features Factory level Fox suspension in the form of their 160mm travel 38 Float EVOL fork with GRIP2 damper, Kashima coated stanchions and 37mm offset with a matching Float DPX2 shock.
The dropper is a RaceFace Turbine R featuring Fox internals, with a 125mm drop on the size Small; 150mm for Medium and Large; and 175mm on the XL. The drivetrain is an all Shimano XT 12-speed affair with a 10-51T cassette, save for the 170mm RaceFace Aeffect R cranks and 34t cinch chainring. Stopping duties are handled by Shimano XT 4-pot brakes with 203mm rotors on both ends. The cockpit is in-house Rocky Mountain components with a 35mm clamp, 40mm stem and 780mm wide bar with 38mm rise. The contact points are handled by Ergon GD1 EVO grip and a 142mm wide WTB Volt saddle, providing the comfort to crunch miles on. The wheelset is a combination of a DT Swiss 350 rear hub with a Rocky Mountain sealed bearing front hub, laced to RaceFace ARC30 rims using burly DT Swiss Alpine spokes. These are shod in Maxxis Wide Trail rubber, with a 2.5” DHF in the front paired with a 2.4” DHR2 out back, both using 3C MaxxGrip rubber compounds and Double Down casings, which should withstand some hard charging. We think all eBikes should be spec’d with Double Down tires and applaud Rocky for making the right call.