ROCKY MOUNTAIN ALTITUDE POWERPLAY CARBON 70

Big power meets big-mountain riding

Photos: Pat Carrigan

Rocky Mountain is unique in the sense that it is still the only bike brand to design and manufacture its own eMTB drive systems. Not wanting to get boxed in by the restraints of second-party designs, the Canadian brand developed its own motor and battery system called Dyname 3.0 four years ago. Rocky Mountain completely redesigned the system for 2020 with version 4.0, and it powers the electric-assist Powerplay line. Complementing the new drive unit are two completely redesigned models—the trail-focused, 140mm-travel Instinct Powerplay and the 160mm-travel, enduro-oriented Altitude Powerplay. The wrecking crew got its hands on the longer-travel version to see if it has the same great characteristics as the non-assist version.

FRAME 

The 29-inch-wheeled Altitude Powerplay Carbon has a carbon front triangle, but that’s where the composite ends. The bike’s chainstays, seatstays and linkage are all made of aluminum. Geometry on this enduro-focused bike is on par with the category. The bike features a 64-degree head angle, 76-degree seat angle and 480mm reach on the size-large test bike. Those numbers are in the RIDE-4 adjustable geometry’s standard neutral setting (Position 3). The RIDE-4 flip chip is located in the shock linkage and allows for four different geometry settings via a single Allen key. Chainstay length is adjustable by 10mm, also via a flip chip, running between 437mm and 447mm long. A full-size water bottle fits inside the front triangle, and the chainstays feature low-durometer guards for silent running.

DRIVE UNIT

The original version was known for its high power output, and the new one retains that characteristic but comes in a smaller and lighter packager—18.5 percent lighter according to Rocky. It is also one of the most powerful motors out there, delivering 108 N/m of torque and 700 watts of peak power output. For reference, Specialized claims 90 N/m of torque for its Brose motor while Shimano’s EP8 and Bosch’s Performance Line CX claim 85Nm. 

How is it more powerful? “The biggest reason is the fact we work at 48 volts.” says Rocky Mountain’s Chief Product Officer, Alex Cogger. “We can push more energy into the motor for the same given amperage, yielding a more powerful output. Obviously, we designed around this voltage to sidestep the potential issues around efficiency, heat management, custom chargers, etcetera. The other great benefit of this 48-volt system is that we have extremely short charging times versus the competition. Shimano, Bosch and Specialized all use a 36-volt system.

The motor layout is unique in that it utilizes a small drive sprocket mounted high on the motor. The cranks are standard-issue mountain bike versions with a regular bottom bracket. Between the cranks and drive sprocket is an idler wheel with the system’s torque sensor that measures rider inputs directly from the chain. Rocky chose this unique layout because its engineers thought they could build a better mousetrap. “We knew we had some amazing technology at our fingertips with our sister company Powercycle Propulsion, and after spending months testing all the competitors in the field, we identified all the pieces of the puzzle we wanted to assemble,” says Cogger. “We wanted a system that had more torque for steeper rides, a bigger battery to support said output, a quieter ride, and we wanted to have the whole thing rider and dealer serviceable.”

Rocky Mountain also designed and created its own 720Wh battery pack that resides in the bike’s downtube. It can be taken out in about a minute by removing the skid plate and single anchor bolt. The battery can be charged on or off the bike, too. There is also a 314Wh overtime add-on battery pack that bolts to the bottle cage mounts for a total capacity of 1,034 Wh.

Rocky Mountain utilizes a unique motor layout. The top sprocket delivers power to the chain, the middle one contains the torque and RPM sensors, while the cranks and bottom bracket are normal off-the-shelf mountain bike parts.

There are two charger options: a 2-amp-hour and 4-amp-hour version. Rocky claims that the 2-amp-hour version will charge a battery from empty in just over seven and a half hours and the 4-amp hour at about half that. Our test bike came with the 4-amp hour version, and our charge times seem to indicate that these estimates are accurate.

Rocky Mountain places a large display on top of the upper downtube called the jumbotron. On that screen, you can see all vital information about the ride and system, including real time statistics, such as motor heat. You can also tune each of the four assist-mode percentages from 0–100 percent, as well as Boost—the way the power comes on when you pedal. The higher the boost, the stronger the assist comes on from your efforts. Since everything can be done on the bike, there is no need for a phone app.

COMPONENTS

Rocky Mountain offers five versions of the Altitude Powerplay, ranging in price from $5749 for the Alloy 30 Coil to $10,469 for the Carbon 90 Rally Edition. We tested the upper-mid-level Carbon 70 build with a Shimano XT drivetrain and brakes. It’s worth noting that the brakes come with non-finned pads and all-steel 203mm rotors—not the steel/aluminum hybrid Ice Tech versions. Cranks are normal Race Face Aeffect Cinch models, and the dropper post is an Aeffect R matched to a Shimano lever. The wheels feature a DT Swiss 370 rear hub with a 24-tooth star ratchet. They are laced to WTB ST i30 tubeless rims and outfitted with the grippy 2.5-inch-wide Maxxis Assegai front and 2.4-inch-wide Minion DHR II rear combo. The icing on the cake? The tires feature heavy-duty Double Down casings, and inside those tires are Cushcore XC tire inserts. That’s right, all Altitude Powerplay models feature Cushcore as a standard feature, and they’re ready to go full enduro right off the showroom floor.

SUSPENSION 

A mid-to-high-pivot Horst-link style four-bar suspension system that Rocky calls Smoothlink gives the Altitude 160mm of travel. The main linkage is higher than most of Rocky’s bikes and is positioned just above the motor’s drive sprocket, much like a bike with a high pivot and an idler pulley. Dual bearings beef up the Horst pivot for eMTB abuse. Eagle-eyed readers might also notice a modular bolt-on aluminum upper shock mount that Rocky says allows for future kinematic updates. It’s a neat future-proof feature that’s only available on the carbon frame versions.

A 170mm-travel Fox Performance Series fork with Grip damper is leading the charge at the front of the Carbon 70 build. The Grip damper features a wide range of low-speed damping adjustments, from wide open and plush to firm but not totally locked out. The Fox Float X2 shock is also a Performance Series model, so it’s all black anodized without the Kashima coating and only has low-speed damping adjustments, not the high-speed adjusters of its factory-level cousin.

The 29-inch Altitude Powerplay Carbon has a carbon front triangle, but the chainstays, seatstays and linkage are all made of aluminum.

CLIMBING

Simply put, this is the most powerful class 1 eMTB that we have tested. While we have no way of confirming the actual output numbers, the claimed power seems to align with our seat-of-the-pants feel and the performance out on the trail. We were able to out-climb similar weight bikes and riders on other systems. The power creates a very different feel.  Compared directly to the organic smoothness of a Shimano EP8 system, the Dyname power feels digital and raw. It sounds different, too, with a low-pitched growl instead of a high-pitched whine.

We really liked the jumbotron interface and ability to tune the assist without an app. You can’t tune it as finely as a Shimano or Specialized system, but we never longed for more. Boost adjustments really changed the feel of the power from a torquey, low-rpm monster to a later-hitting feel with more rider effort required to get it.

Another unique trait is system drag. You can really feel it while pedaling with the assist off, and some riders thought that they might have felt it in the lower-assist levels, too. It’s far from a deal breaker, though. On a mixed group ride (both eMTB and MTB), we toggled between off and 25-percent assist to maintain pace, but it does feel like it has more drag than other systems.

“Simply put, this is the most powerful class 1 eMTB that we have tested.” 

All that power comes at a price in the form of heat. On two occasions the motor reached an internal temperature high enough for the system to reduce power and protect itself. The first time was when a novice rider used Ludicrous mode with Boost settings at max to keep up with a wrecking crew member on a regular bike up a steep, long, fire road climb. The rider was relying heavily on the assist to get up the hill—something this system does very well with a high cadence. 

The second time it got hot was when we tried to replicate the situation on a longer, steeper climb. We spun a high cadence using little of our own strength to do it. Even when the motor was hot, there was enough power to finish the climb, and it returned to normal after it cooled down. It will shut off completely when it reaches 90 degrees centigrade, but we were never able to get it above 86 degrees. This did not happen in normal riding situations, but we mention it because it might be an issue for bigger riders who like to boost up long, steep climbs with little exertion.

DESCENDING

As one might expect with an enduro-focused bike like this, the Altitude feels very at home any time the trail turns downward. But unlike other bikes in its class that feel big and brutish, the Rocky stays light on its feet and agile. It’s one of those bikes that feels big when you need it and spry when you don’t. Its suspension action is superb and predictable on the roughest trails, too

“In spite of some quirks, Rocky Mountain knocked it out of the park with the Altitude Powerplay. It’s a rocket ship on the climbs and performed like a modern enduro bike on the descents.” 

As with other adjustable bikes, we tried all settings on the Altitude. For general riding, we preferred the standard high setting. This is an aggressive bike that doesn’t need to be slackened to work right out of the box, but we are happy to have options. We also tried both chainstay settings and strongly preferred the shorter one. In the short setting, the front felt light and easy to place wherever you wanted. In the longer setting, it felt heavy and had a tendency to push in steep, soft corners.

Overall, the Altitude reminded us a lot of the Yeti 160E in terms of overall feel and performance but with a slightly different attitude. Both have excellent suspension and a light feel on the trail. The Yeti seems more eager for speed whereas the Altitude is slightly more at home on steeper slopes and rugged trails.

MODS AND UPGRADES 

This is a bike that’s spec’ed so well that little is needed in terms of upgrades. Rocky uses 170mm-long crank arms on size large and extra-large or 165mm on small and medium. Those who ride and climb in rocky terrain will likely want to shorten the crank arm length to reduce pedal strikes. Although power and feel are superb, on super-long and steep descents we experienced a touch of heat-related fade and squeal from the XT rear brake. We would upgrade to a bigger rotor, Ice Tech rotor, Ice Tech pads or all three if it becomes an issue. It’s also worth noting that the downtube shuttle guard hardware can scratch the fork’s top caps, so some sort of protector over its metal pieces might be smart.

BOTTOM LINE

In spite of some quirks, Rocky Mountain knocked it out of the park with the Altitude Powerplay. It’s a rocket ship on the climbs and performed like a modern enduro bike on the descents. Great components and thoughtful features check all of the wrecking crew’s eMTB wish-list boxes. From short bike-park-style laps to a 31-mile loop with 7000 feet of climbing and a 10-mile-long descent, this bike did it all and did it all exceptionally well. If you’re looking for a versatile, heavy-hitting enduro-focused eMTB, run, don’t walk, to your local Rocky Mountain dealer, because this one is going to be extremely popular.

CATEGORY

eMTB Enduro

WHEEL SIZE

29″

SUSPENSION

170mm-front

160mm-rear

Rocky Mountain Altitude Powerplay Carbon 70

Price: $9059

Weight: 53.5 Pounds (without pedals)

Sizes: S, M, L (tested), XL

Frame tested: 160mm travel, carbon/aluminum

Shock: Fox Float X2 Performance

Fork: Fox 38 Float EVOL GRIP Performance Series

Wheelset: B ST i30 TCS 2.0 Tubeless aluminum rimsWT

Tires: Maxxis Assegai 2.5″ WT 3C MaxxGrip DD tubeless-ready (front); Maxxis Minion DHR II 2.4″ WT 3C MaxxTerra DD tubeless Ready; Cushcore XC tire inserts (rear)

Seatpost: Race Face Aeffect R (175 mm travel)

Saddle: WTB Volt Race 142

Handlebar: Rocky Mountain AM, 780mm width

Stem: Rocky Mountain 35 AM, 40mm

Grips: ODI Elite Pro Lock On

Headset: FSA Orbit NO.57E

Brakes:  Shimano XT Trail 4-piston

Rotors: Shimano RT66, 203mm (f)/203mm (r)

Rear derailleur: Shimano XT

Shifters: Shimano XT

Crankset: Race Face Aeffect Cinch

Bottom bracket: FSA BB89.5 24mm

Cassette: Shimano XT 12-speed, 10-51T

Chain: Shimano M8100

Chainrings: 34-tooth

GEOMETRY (RIDE-4 Position 3)

Head tube angle: 64°

Reach: 480mm (18.9″)

Stack: 634mm (24.96″)

Effective seat tube angle: 76°

Bottom bracket height: 345mm (13.6″)

Chainstay length: 437mm (17.2″)

Wheelbase: 1262mm (49.68″)

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carbon e-bikeRocky mountainROCKY MOUNTAIN ALTITUDE POWERPLAY CARBON 70rocky mountain e-bike