The design goal for the new Stumpjumper was simple—build the ultimate trail bike, one that feels telepathic. And it turns out that this feeling all comes down to stiffness.
Think of it this way: when the frame's telling your hands one thing and your feet another, your brain gets confused with the imbalance and the bike feels unstable. In order to fix this, we had to get to work on dialing-in the materials, shapes, and the layout.
We started by creating our own mountain-specific stiffness test, and then we looked at the layout with Finite Element Analysis (FEA) to see where we could get the biggest stiffness improvements. This led to a big discovery: The Large and X-Large frames needed more front-end stiffness while the Smalls and Mediums were just fine. We were able to create a frame design that was 20% more efficient. And in the end, this proved to be one of the lightest trail frames on the market, today.
We continued down the suspension path with a custom Rx Trail Tune on both the fork and rear shock. Suspension performance is highly dependent on frame, wheel, and rider size, so we use our Rx Tune to get each bike to land in the middle of the adjustment spectrum, and this gives you the biggest possible range to fine-tune your ride. Another focal point of the tune was matching the suspension characteristics between wheel sizes—we developed a specific Rx Tune for each platform. So, no matter what wheel size you prefer, you’ll get perfectly linear suspension.
Steps were also taken to make this bike easy to live with. Threaded bottom brackets make a triumphant return, and we made room for up to a 3.0" tire. You're also free to run whatever aftermarket rear shock you want, since we're using standard metric shocks. We revamped the SWATª box, too, making it sleeker, lighter, and with more volume. And customization is furthered with a Flip Chip that lets you to dial-in your Stumpy to your riding style. Switch it from High to Low and it drops your bottom bracket 6mm and slackens the head tube by half-a-degree. Little details also jump out to surprise you, like a newly designed ribbed chainstay protector that makes chain slap a thing of the past and nearly silences the drivetrain. Lastly, we seriously couldn’t make cable routing any easier on carbon models. Full tubes can be found throughout the carbon frame, so all you have to do is push the cable and it’ll come out the other end. No more lazy loop, hidden stashes of magnets, pokey spokes, or pillows to cry in.
For the build, you get a components package that's the perfect blend of performance and affordability—a full SRAM GX Eagle drivetrain, SRAM Guide RS disc brakes, FOX Factory front and rear suspension (150/140mm of travel respectively), and Roval Traverse Carbon 29 wheels.
|FRAME||FACT 11m, full carbon chassis and rear-end, asymmetrical design, 29 Trail Geometry, SWATª Door integration, threaded BB, fully enclosed internal cable routing, 12x148mm dropouts, sealed cartridge bearing pivots, replaceable derailleur hanger, 140mm of travel|
|FORK||FOX FLOAT 36 Factory, GRIP2 damper, Kashima Coating, 15x110mm, 51mm offset, 150mm of travel|
|REAR SHOCK||FOX FLOAT DPX2 Factory, Rx Trail Tune, EVOL Air sleeve, Kashima coat, 3-position adjustment w/ Open Mode adjustment, 210x50mm|
|FRONT HUB||Specialized, sealed cartridge bearings, 15x110mm spacing, 28h|
|REAR HUB||DT Swiss 350, Star Ratchet, 36t engagement, SRAM XD driver body, 12mm thru-axle, 148mm spacing, 28h|
|SPOKES||DT Swiss Industry|
|RIMS||Roval Traverse Carbon 29, hookless carbon, 30mm inner width, hand-built 2Bliss Ready, 28h|
|INNER TUBES||Standard, Presta valve|
|FRONT TIRE||Butcher, GRID casing, GRIPTON® compound, 2Bliss Ready, 29x2.6"|
|REAR TIRE||Purgatory, GRID casing, GRIPTON® compound, 2Bliss ready, 29 x2.6"|
|CRANKSET||Truvativ Descendant, aluminum, Boostª 148, 170mm crankarm, 24mm spindle|
|BOTTOM BRACKET||SRAM GXP|
|SHIFT LEVERS||SRAM GX Eagle, trigger, 12-speed|
|REAR DERAILLEUR||SRAM GX Eagle, 12-speed|
|CASSETTE||SRAM GX Eagle, 12-speed, 10-50t|
|CHAIN||SRAM GX Eagle, 12-speed|
|FRONT BRAKE||SRAM Guide RS, hydraulic disc, organic pads, Guide S4 4-piston caliper, 200mm rotor|
|REAR BRAKE||SRAM Guide RS, hydraulic disc, organic pads, Guide S4 4-piston caliper, 180mm rotor|
|HANDLEBARS||Specialized Trail, 7050 alloy, 8-degree backsweep, 6-degree upsweep, 27mm rise, 780mm, 31.8mm clamp|
|GRIPS||Specialized Sip grip, half-waffle, S/M: regular thickness, L/XL: XL thickness|
|STEM||Specialized Trail, forged alloy, 4-bolt, 5mm rise|
|SADDLE||Body Geometry Phenom Comp, hollow Cr-Mo rails, 143mm|
|SEATPOST||Command Post IRcc, 16-position micro-height adjustable, two-bolt head, bottom mount cable routing, remote SRL lever, 34.9mm, S: 130mm, M/L/XL: 160mm of travel|
|SEAT BINDER||Specialized bolt-type, alloy, 38.6mm|