Rocky Mountain is the latest company to announce a 27.5"-wheeled machine for 2013. The new Altitude range of 6"-travel trail bikes will be launched exclusively with the resurrected middle wheel size for what the Canadian company claims is faster rolling than traditional 26" hoops without the long-travel design restrictions of 29" ones.
Other than the name, Rocky Mountain has retained little of the outgoing model with travel bumping up to 150mm at both ends, a new rear suspension layout, updated (and impressively adjustable) geometry, and a sleeker overall look that integrates more up-to-date features that have already been included in other Rocky Mountain models.
The new Altitude retains the general SmoothLink four-bar rear suspension design but switches from last year's rocker-link setup to a top tube-mounted link and rear shock configuration borrowed from the Element range. Rocky Mountain will also bring the Element's ABC (Angular Bushing Concept) angular contact polymer bushings into its new trail bike range at the dropout and shock link pivots for what the company claims is a 105-percent boost in rear end stiffness, 120g less weight, and less maintenance as compared to conventional sealed radial cartridge bearings. Cartridge bearings are still used in the main pivot, though.
The new Altitude features a top tube-mounted link and rear shock configuration
One of the new Altitude's most appealing features is Rocky Mountain's new RIDE-9 system, which offers a remarkably wide range of geometry and suspension customizationvia two pairs of nested chips at the forward shock mount that can be independently rotated. This not only adjusts the handling (head tube angle ranges from 66.6-68.3° and bottom bracket drop from 10mm to -10mm) but also the shock rates so that the bike can be more finely tuned for heavier or lighter riders that might otherwise have to run pressures above or below the intended range.
Naturally, Rocky Mountain claims the new Altitude will not only gobble up trail obstacles but will also be efficient to pedal. The starting shock rate is intentionally steep for the first 20mm of travel – what Rocky Mountain calls the 'Pedaling Platform Zone' – but then flattens out for a more active and pillowy mid-stroke. The rate ramps up again after about 110mm or so, though, for controlled bottom-out.
Notably, Rocky Mountain achieves this through the linkage kinematics, not overly heavy damper rates, so the new Altitude should presumably be reasonably active on smaller impacts, too.
Other features include a tapered front end, internal cable routing (including for newer dropper posts like RockShox's Reverb Stealth and remote rear shocks), an extra-wide BB92 bottom bracket shell with press-fit bearing cups and ISCG05 chain guide tabs, a 142x12mm thru-axle rear end with a repositionable Shimano/Fox quick-release skewer, stainless steel chainsuck plates on the down tube and chain stay, and even a rubber coated seatpost collar designed to prevent water and grime from infiltrating the seat tube.
Rocky Mountain's new 27.5" 790 MSL Carbon trail bike
Rocky Mountain will offer the new Altitude in five sizes and five models starting in early spring. Claimed frame weight for the full carbon version is approximately 2,300g (5.07lb).
The top-end Altitude 790 MSL (which will also be offered as a bare frame for US$2,799.99) is built with a carbon fiber front triangle and rear end, a Fox 34 Float 150 FIT CTD Kashima fork and remote Float CTD rear shock, SRAM X0 2x10 transmission and X0 Trail four-piston brakes, DT Swiss tubeless-ready wheels wrapped with Schwalbe rubber, a RockShox Reverb Stealth dropper seatpost, and Race Face cockpit components. Suggested retail price is US$6,899.99.
The Altitude 770 MSL retains the carbon front end, Reverb Stealth seatpost, Race Face cockpit, and Schwalbe tires but switches to an aluminum rear triangle, non-Kashima coated Fox suspension components, a Shimano Deore XT 2x10 transmission (with a Race Face Turbine crank), andRocky Mountain house-brand wheels. Suggested retail price is US$5,399.99.
Moving further down the line is the US$4,499.99 Altitude 750 MSL, which uses the same carbon and aluminum frame, rear shock, crank, dropper post, and wheels as the 770 MSL but an open-bath Fox 34 Float fork, a mix of SRAM X7/X9 and Avid Elixir 50 componentry, and heavier cockpit parts.
The standard Altitude 750 moves to an all-aluminum frame, a Shimano Deore XT/SLX 2x10 transmission and Race Face Evolve cranks, and a fixedseatpostfor US$3,399.99 while the entry-level Altitude 730 will come with a RockShox Revelation RL Solo Air fork and Monarch RT rear shock, SRAM X5/X7 2x10 componentry, and heavier house brand wheels and Race Face cockpit components for US$2,849.99.
Pricing and availability for the new Altitude models is still to be announced.
New Slayer SS chassis for slopestyle, too
Rocky Mountain has also announced a new dedicated slopestyle machine called the Slayer SS, which uses the current Slayer aluminum tubeset but with just 100mm of firmly tuned rear end travel for heavy landings.
The one-size-fits-all geometry is specific for the genre with short 406mm chain stays (there is no provision for a front derailleur), a rangy 610mm (24") effective top tube, a 69-degree head tube angle, and a very stable 25mm of bottom bracket drop.
The new Rocky Mountain Slayer SS
Additional features include a tapered front end, ISCG03 chain guide tabs, and a 142x12mm thru-axle rear end.
Complete bikes will come with a RockShox Monarch R rear shock, Manitou Circus Expert fork, Race Face cockpit components, 27mm-wide Sun-Ringlé Inferno rims, TruvativRuktion cranks, an e13 LS1+ chain guide, Avid Elixir 1 brakes, a SRAM X7 1x9 transmission, house brand wheels, and Geax AKA tires.