Rocky Mountain Thunderbolt 770
Frame and Component Details
Rocky Mountain's new Thunderbolt is the Canadian company's take on a 27.5” wheeled XC / trail bike. Designed with cross-country riding in mind, the bike has an aluminum frame and 120mm of travel, but lacks the steep head angle (and twitchy handling) commonly associated with a purebred XC race bike. Rocky's designers wanted the bike to be more of an all-rounder, so they gave it a 68.5 degree head angle and 427mm chainstays, numbers intended to make for a lively ride that's still competent on the descents.
Thunderbolt 770 Details
• Intended use: XC / trail
• Hydroformed aluminum frame
• Rear wheel travel: 120mm
• Wheel size: 27.5"
• Head angle: 68.5 degrees
• Smoothlink Suspension
• MSRP: $3999.99 USD
The Thunderbolt uses Rocky Mountain's Smoothlink Suspension for its 120mm of travel. It would be easy to mistake this suspension layout for a Horst link design, but take a closer look - the chainstay pivot is actually located above the rear axle, a design derived from Rocky's ETS suspension patent. According to Rocky, this pivot position gives them a wider range of gears where the suspension remains unaffected by pedalling, and also lets them manipulate the rear shock's end-stroke behavior to prevent harsh bottom outs. The inclusion of a CTD remote is the reason for this much housing at the front of the bike, but internal cable routing helps tuck some of it out of sight. The Thunderbolt's parts kit includes a healthy dose of Race Face and Shimano components.
The bike's hydroformed aluminum frame has a tapered head tube, internal cable routing (including the option for stealth dropper post routing
), and a 12x142mm rear thru axle. There are four models in the Thunderbolt lineup, with prices starting at $2099 USD for the Thunderbolt 710. The top tier 770 model (3999.99 USD
) we checked out comes smartly specc'd with a mix of Shimano and Race Face components, including Shimano's XT brakes, an XTR rear derailleur, and Race Face's Turbine cranks. The bike rolls on Shimano XT hubs laced to pair of Stan's ZTR Crest rims and shod with Continental's X King 2.2” tires. Fox takes care of the Thunderbolt's suspension, with a Fox 32 120 Float CTD front fork and a Float CTD rear shock. A handlebar mounted remote ties the suspension together and lets riders switch between Climb, Trail, and Descend modes on both the front and rear shock by pushing the thumb activated lever. Fox's CTD remote has been refined for 2014. The grey lever pulls cable to move to Trail or Climb mode, and the black lever releases cable and returns the fork and shock to Descend mode.Initial Impressions
The Thunderbolt is a nimble climber, with a fairly upright climbing position that made it easy to balance our weight over the front or rear of the bike as needed. With the rear shock all the way open there was some suspension movement during hard pedaling, but it was nothing that couldn't be fixed with a quick push of the CTD remote lever. Although we're not typically fans of extra handlebar mounted accessories, we ended up using the CTD remote more than expected. Want a firmer platform for a smooth section of trail or an out of the saddle sprint? Push the lever into Trail or Climb mode and pedal away to your heart's content. When things start to get rugged, give it another push and Descend mode puts the suspension into its plushest setting. Having the remote made us more likely to utilize the full range of shock settings since it wasn't necessary to take a hand off the handlebar to switch modes.
On the descents the Thunderbolt had a puppy-like eagerness, darting down the trail and sniffing out every little feature to pop off of. It's easy to get it airborne, and just as easy to get set up for landing. The Thunderbolt's stock spec is perfect for its XC / trail intentions, but our preferred riding style and terrain had us scheming how to eke even more performance out of it. A wider handlebar, meaty tires, and a stouter front fork with slightly more travel could make this into an absolute shredder, a playful, short travel trail bike with enough guts to confidently pick its way through the tricky, technical stuff. Still, the current spec is well thought out (although lacking a dropper post
), with a solid parts package well suited to a bike that's meant for long trail rides, but could still roll up to an XC race and hold its own. www.bikes.com