Dirt Rag Magazine

First look: 2013 Rocky Mountain Altitude 650b

By Adam Newman, action photos by Margus Riga,

When Rocky Mountain set out to redesign the genre-bending Altitude trail bike they had a broad stroke of travel lengths – and wheel sizes – to choose from. When the dust settled, the 650b wheels were combined with 150mm of travel and a novel, adjustable-geometry linkage.

Ride 9

Bikes in the slightly ambiguous "trail" category run the gamut from burly XC speedsters to stripped-down gravity sleds, so Rocky Mountain incorporated an all new technology in the Altitude: Ride 9. By adjusting two concentric squares at the upper shock mount, the rider has nine adjustment points to choose from. By effectively moving the shock mount forward and back they can adjust the headtube and seattube angles as well as bottom bracket drop. Check out how the changes work on the fly with Rocky Mountain’s Ride 9 microsite.

Alternatively, by moving the mounting point up or down, it will change the amount of force required to bottom out the shock, useful as riders can vary in weight as often as they do height. WIth the shock mounted in the upper portion of the square it requires a higher air pressure, useful for lighter riders to prevent an under-pressurized shock. In the lower positions of the square, heavier riders won’t require as much air in the shock.

By adjusting the chip, the rider can adjust the Altitude’s headtube angle from 66.6 to 68.3 degrees, the seattube angle from 73.6 to 75.3 degrees, and the bottom bracket height by plus or minus a full 10mm above or below the axle line. All sizes share a 428mm chainstay length. If the seattube numbers seem steep to you, it’s because Rocky Mountain runs what it calls Straight Up geometry, keeping the rider from falling too far behind the bottom bracket when the bike is sagged.

The bike also incorporates Rocky Mountain’s Angular Contact Bushings first introduced on the Element 29er platform, saving a full 120 grams over sealed bearings and what it claims is twice the rear end stiffness.

Rocky Mountain uses a patented SmoothLink suspension system that keeps a straight line from the main pivot to the rear pivot above the axle line at all points of travel. By keeping the rear pivot low, it achieves a near parallel path to the pull generated by the chain. The bike I rode was a pre-production prototype aluminum model with a mixed parts spec, but it was more than capable of tackling the trails surrounding Whistler, BC. The suspension seemed quite active, and I made good use of the Fox CTD remote while shuttling, but I didn’t have time to really fine-tune the shock pressure.

 

With the Ride 9 adjustment chip moved to a more slack and firm platform for the second half of the ride, the change to the headtube angle made for a subtle, but noticeable difference in the bike’s descending stability. Given the trend in geometry and rider preference for longer, lower, slacker in recent years, I can’t imagine many riders opting for the steeper setting.

As with other 650b bikes I’ve ridden in this segment, the wheel size plays a smaller role in bike’s overall character than you might imagine. Unlike the jump to 29-inch, it takes a second of looking at a 650b bike to notice the increased diameter, and the same subtle difference is felt on the trail as well. The Altitude never feels long or awkward, and can handle tight moves without sacrificing roll-over ability.

 

 

  

There will be five spec levels in all: A full-carbon 790 MSL, the carbon front/aluminum rear 770 MSL and 750 MSL, and full-aluminum 750 and 730. The full-carbon version will be available as a frame-only option. All models share a 142mm thru-axle, ISCG chain guide mounts, a BB92 bottom bracket, 2×10 drivetrains, Shimano direct-mount derailleur hangers, and cable routing for dropper seatposts and rear shock remotes.

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