Ever had a ride that felt more like an experience than just a ride? Us, too, and we've been chasing that feeling ever since. With the Stumpjumper Expert 27.5, we've bottled up that feeling and put into a radical new frame design that's so agile, lively, and in-tune with the trail, the bike feels like an extension of your body. Seriously, it's going to make you rethink how a trail bike should ride.
Our design goal for the new Stumpjumper was simpleÂ—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.
When designing the frame with the stiffness targets being a main goal, we developed a radical new sidearm design. The front-end and rear-end are connected at three points, and the sidearm helps keep all these points super stiff and connected, all while taking about 100 grams out of the rear-end. More explicitly, this minimizes frame flex when the rear suspension is active.
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 sizesÂ—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
The Stumpjumper's asymmetrical, FACT 11m carbon fiber construction is lightweight, stiff, and ready to take on the trail. It's built off our 27.5 Trail Geometry, so it's just the right amount of both capable and comfortable. And with SWATÂ™ integration in the down tube, a threaded BB, easy cable routing, and an all new chain silencer, it's ready for anything the trail, or you, throw at it.
With three different compression adjustmentsÂ—open/pedal/lockÂ—incredible damping performance, and our Rx Trail Tune, the RockShox Deluxe RT3 perfectly complements the Stumpjumper.
RockShox's Pike is known for its trail performance, and the RC found here has stiff stanchions, a Charger damper, and plenty of sensitivity.
Type: Dual Suspension Mountain Bikes
Size: Small, Medium, Large, XL
Frame in inches: 15.5", 17", 18.5", 20.5"
Colour: Blue, Grey
Riding Style: Trail
Wheel Size: 27.5"
Rear Derailleur: SRAM GX Eagle
Item condition: New
FACT 11m, full carbon chassis and rear end, asymmetrical design, 27.5 Trail Geometry, SWATÂ™ Door integration, threaded BB, fully enclosed internal cable routing, 12x148mm dropouts, sealed cartridge bearing pivots, replaceable derailleur hanger, 150mm of travel
RockShox Pike RC, DebonAir, rebound/low-speed compression adjust, tapered steerer, 46mm offset, 15mm MaxleÂ® Stealth thru-axle, 15x110mm BoostÂ™, 150mm of travel
RockShox Deluxe RT3, Rx Trail Tune, rebound and 3-position compression adjust, 210x52.5mm
Specialized, sealed cartridge bearings, 15x110mm spacing, 28h
Specialized, sealed cartridge bearings, 12x148mm thru-axle, 28h
DT Swiss Industry
Roval Traverse Carbon 27.5, hookless carbon, 30mm inner width, 28h, tubeless ready, hand-built
Presta, 40mm valve
Butcher, GRID casing, GRIPTONÂ® compound, 2Bliss Ready, 27.5 x 2.6"
Purgatory, GRID casing, GRIPTONÂ® compound, 2Bliss Ready, 27.5 x 2.6"
Truvativ Descendant, aluminum, BoostÂ™ 148, 170mm crankarm, 24mm spindle
SRAM GX Eagle, trigger, 12-speed
SRAM GX Eagle, 12-speed
SRAM GX Eagle, 12-speed, 10-50t
SRAM GX Eagle, 12-speed w/ PowerLockÂ®
SRAM Guide R, hydraulic disc, organic pads, Guide S4 4-piston caliper, 200mm rotor
SRAM Guide R, hydraulic disc, organic pads, Guide S4 4-piston caliper, 180mm rotor
Specialized Trail, 7050 alloy, 8-degree backsweep, 6-degree upsweep, 27mm rise, 780mm, 31.8mm clamp
Specialized Sip Grip, half-waffle, S/M: regular thickness, L/XL: XL thickness
Specialized Trail, forged alloy, 4-bolt, 5mm rise
Body Geometry Phenom Comp, Adaptive Edge design, hollow Cr-Mo rails, 143mm
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