Rocky Mountain Debuts 650b “Thunderbolt” Model

Four new models sport 120 millimeters of travel, "27.5-inch" wheels & a playful ride quality

Rocky Mountain Bicycles unveiled a new model today–the Thunderbolt–a bike that blurs the lines between cross-country efficiency and trail bike confidence. Or, to quote the press release, “When XC gets rowdy, the incredibly agile Thunderbolt shines…. At last, an XC bike dedicated as much to flowy singletrack as to punchy technical climbs.”

Rocky Mountain’s engineers aimed to create a more confident and playful version of cross-country racer. To that end, the Thunderbolt sports a relatively slack 68.5-degree headtube angle, a short rear center, longer top tube, wide bars, short stem and five inches of squish. While you might argue that they equipped the bike with 27.5/650b wheels because doing anything else seems like market suicide these days, Rocky contends that the wheel size is perfectly suited to their desire to give the bike a more playful and agile feel than that typically afforded by a 29er platform.


There are four Thunderbolt models in the 2014 line up, all of which sport 7005 aluminum frames. Here are some key features, common to all four Thunderbolt bikes.

Key features
• 142mm E-Thru rear axle to increase stiffness (Thunderbolt 710 utilizes F/R quick release).
• Internal cable routing keeps cables neatly stowed, with service-friendly ports.
• Internal "Stealth" dropper-post routing tucks the housing inside the frame for minimal clutter (with
external option).
• BB92 pressfit bottom bracket provides maximum lateral stiffness.
• XC tuned Smoothlink™ design delivers exceptional climbing traction and stable pedalling platform.

Feel like geeking out on geometry charts? It takes all kinds. If that’s your cup of dweeb, check this out.