Rocky Mountain has remade the Thunderbolt for 2018, increasing the rear wheel travel in the standard Thunderbolt model from 120mm to 130mm. The new Thunderbolt features 130mm of travel both front and rear, and the BC Edition adds a long stroke shock and a longer-travel fork to the Thunderbolt frame for 140mm of travel on both ends.
The Thunderbolt’s new Smoothwall carbon frame also increases stiffness over the previous model, “lowers the rate curve slightly, and gives the frame a host of next-generation features—but keeps its playful geometry and wide range of RIDE-9™ adjustments,” according to Rocky Mountain.
Those next-generation features include things like one-sided bearing pivots (like the pivots featured on the Slayer I tested), tooled axles, an integrated “Spirit Guide” chainguide, and metric shock spacing. The frame is also compatible with Di2 and Fox Live, and a dropper post at the same time.
Other features include a 1x optimized design, size-specific tunes to ensure that the shock is tuned to match the weight of the rider, shorter seat tube lengths for maximum dropper post space, chainstay and downtube protectors, and space for a water bottle in the front triangle even with a piggyback rear shock. While all stock models come with standard 27.5″ wheels and tires, the Thunderbolt is compatible with 27.5″ Wide Trail tires and 26+ tires as well.
The frame is available in sizes from XS to XL, with the frame + shock weighing 2.30kg/5.06lbs in the size-medium. Rocky notes that the protectors, chainguide, and axle add 260g/0.57lb, for a complete frameset weight of 2.56kg/5.63lbs. The complete Thunderbolt Carbon 90 BC weighs a claimed 12.57kg/27.7lbs, and the standard Carbon 70 weighs a claimed 11.80kg/26.0lbs.
The Thunderbolt geometry has been tweaked as well, with an “increased reach, slackened head tube angle, and [lower] bottom bracket,” according to Rocky. “We’ve slightly lengthened the chainstays to improve climbing traction and used a moderately steep seat tube for further climbing performance.”
Rocky Mountain Thunderbolt Carbon Geometry
The new head tube angle measures 66.4°, 67°, or 67.6° depending on the Ride-9 position. The seat tube angle is 74.4°, 75°, or 75.6°. The rear center, aka the chainstay length, is 426, 425, or 424mm. And finally, in a size-large the reach is either 458, 463, or 469mm.
For more deets, check out the geometry charts below.
Rocky Mountain Thunderbolt Carbon BC Edition Geometry
In the BC edition, the new head tube angle is slightly more slack at 65.9°, 66.6°, or 67.1° depending on the Ride-9 position. The seat tube angle is 73.9°, 74.6°, or 75.1°. The rear center, aka the chainstay length, is 426, 425, or 424mm. And finally, in a size-large the reach is either 458, 463, or 469mm.
For more deets, check out the BC Edition geometry charts below.
Rocky Mountain Thunderbolt Build Kits
The new Thunderbolt is available in four build kits, each built around a carbon frameset: the Carbon 90 BC Edition for $5,999 USD, Carbon 70 for $5,399, Carbon 50 for $4,499, Carbon 30 for $3,499, and the BC Edition Frameset for $2,599.
Highlights of the new Thunderbolt Carbon 90 BC Edition include an integrated chainguide, along with a Fox 36 DPS Performance Elite fork, SRAM GX Eagle 12-speed drivetrain, SRAM Guide RS brakes, and a Fox Transfer dropper post.
Highlights of the standard Carbon 70 model include an integrated chainguide, SRAM GX Eagle 12-speed drivetrain, a DT Swiss 370 rear hub, and a Fox Transfer dropper post.
The new Thunderbolt is available at dealers immediately, although regional availability may vary.