Again in July, Specialised introduced the up to date Stumpjumper 15 carbon – As of in the present day, the alloy fashions have arrived. The Stumpjumper has at all times been a flexible path bike, and its newest updates together with elevated rear journey, adjustable geometry, and new Genie rear shocks have affirmed its standing as a top-tier ‘do something’ path bike.
Specialised has determined their carbon Stumpys ought to serve the higher-end market, whereas the alloy fashions supply lower-spec builds that come proper all the way down to entry-level costs. Nevertheless, the alloy bikes get the identical adjustable body geometry and suspension kinematics because the pricier carbon fashions. Two of the entire builds additionally include the brand new extremely adjustable Genie rear shocks Specialised debuted with the carbon Stumpys.
Stumpjumper 15 Alloy – Body Options:
The brand new Stumpjumper 15 Alloy frames are constructed from M5 Alloy. Just like the carbon model, the alloy body’s entrance finish, rear finish, and hyperlink had been designed to make sure they work collectively to supply the quantity of stiffness Specialised meant. Additionally just like the carbon Stumpy, there is no such thing as a longer a ‘sidearm’ on the alloy body. Specialised realized they may reinforce the hyperlink as an alternative, which affords a cleaner have a look at the identical weight because the outgoing design.
The Stumpjumper 15 Alloy comes with 29” wheels on S3-S6 frames, and MX wheels on S1 and S2 frames… besides the Fox Coil mannequin, which runs MX wheels on all body sizes. S2-S6 body sizes are mullet appropriate by including aftermarket shock hyperlinks which keep the body’s geometry and kinematics with the 27.5” rear wheel.
Six geometry settings are potential between the body’s adjustable head angle and BB peak, providing a variety of tunability to go well with totally different terrains or driving types. The pinnacle angle is adjustable by swapping out the headset cups. Impartial cups come pre-installed, and +/- 1° cups are included with every bike. BB peak is adjusted through a flip-chip on the rear finish of the chainstays.
The up to date Stumpjumper 15 Alloy body does get Specialised’s SWAT down tube storage compartment. On the alloy Stumpys, the storage door is similar because the one discovered on the aluminum Stumpjumper EVOs. The brand new flush-mount door launched on the carbon Stumpjumper 15 wouldn’t work resulting from a distinction in tubing thickness. Specialised did say the quantity of area inside is similar to the carbon fashions. A zippered software bag is included with every bike.
The alloy Stumpy frames get inside cable routing with entry ports on the down tube. In contrast to the carbon model, the alloy frames get routing for a rear derailleur cable, so that you’re not caught with wi-fi drivetrains solely!
Dropper publish journey numbers range as Specialised shares totally different manufacturers on totally different fashions, however relaxation assured all body sizes supply sufficient room for ample size posts. For instance, S2’s come inventory with 150mm posts and S3s run 170mm posts. The Stumpy body accepts 34.9mm posts.
The frames additionally go away loads of area for water bottles. I reviewed the carbon Stumpjumper 15 Professional this summer time and the S3 body match a big bottle simply. Facet entry SWAT bottle cages are included on all fashions.
Different key fitments embody Enhance 148mm rear axle spacing, a 73mm threaded BB, and SRAM UDH-compatible dropouts. For body safety, the bike contains chainstay/seatstay guards, and a decrease down tube guard.
If you happen to are inclined to maintain bikes for the lengthy haul you’ll be comfortable to listen to Specialised now affords free lifetime alternative of all linkage pivot bearings to the unique proprietor.
Suspension:
The Stumpjumper 15 alloy affords 145mm of rear journey pushed by Specialised’s FSR linkage. Fork journey is 140mm on S1 frames, and 150mm on all others… besides the Fox Coil mannequin, which runs a 160mm fork on all body sizes.
Specialised strove to make sure the brand new Stumpjumpers would supply nice small-bump sensitivity, the vigorous experience you’d need from a mid-travel bike, and loads of functionality to soak up arduous hits from tough terrain or large drops.
The Stumpy’s FSR linkage was tuned to require little or no pressure to get into its mid-travel vary. In comparison with the Stumpjumper EVO, the brand new Stumpy will use 100mm of journey dealing with the identical quantity of influence pressure that may use 86 mm of the EVO’s journey. This preliminary softness goals to make the stumpy really feel prefer it has extra journey than it actually does (and after driving the carbon model, I’d agree it does accomplish this). The tune additionally leads to higher bump-force administration and considerably improved traction versus the Stumpy EVO.
To make sure glorious pedaling prowess, the Stumpy’s anti-squat was fine-tuned to sit down proper between the earlier Stumpjumper and Stumpy Evo fashions.
Genie Rear Shocks:
Specialised’s new Genie-equipped Fox Float Efficiency rear shocks come on the Comp mannequin and alloy frameset. They don’t seem to be included on the Fox Coil mannequin or the bottom ‘Alloy’ mannequin. This can be a good time to level out that whereas the Genie shock was developed alongside the Stumpjumper, the bike can run different rear shocks.
For a full rundown of the Genie shock know-how, take a look at my Stumpjumper 15 carbon launch article. In brief, right here’s the way it works: The shock incorporates a distinctive outer air chamber, and Genie sleeves inside that slide forwards and backwards because the shock compresses and expands. The outer air chamber stays open for the primary 70% of journey, and with that added to the shock’s typical internal air chamber the additional quantity may give the shock a extremely delicate, coil-like experience really feel. Nevertheless, the spring price of the outer air chamber is tunable: By including spacers to that chamber, you may scale back the general air quantity within the shock and produce a extra supportive, vigorous experience.
What’s necessary to notice is these changes solely have an effect on the primary 70% of the shock’s journey. At 70%, the Genis spacers slide over a set of ports and shut off the outer chamber. The final 30% of journey will get extra progressive because the air quantity within the shock is immediately lowered. Moreover, the internal chamber’s shock price is individually tunable utilizing typical eyelet quantity spacers.
Specialised has added an additional air quantity chamber to the shock with out utilizing a piggyback or distant accent, and so they’ve made it so each bottom-out resistance and the mid-travel vary you spend most of your time driving inside may be tuned individually.
Geometry:
Stumpjumper 15 Alloy frames can be found in sizes S1 – S6. The Stumpy Alloy’s geometry is strictly the identical because the carbon fashions.
Please be aware: Because of the longer 160mm fork and 27.5” rear wheel on the Fox Coil mannequin its geometry varies barely from the opposite fashions, and it isn’t obtainable within the S1 body dimension. See Specialised’s web site for the coil mannequin’s geometry.
Specialised has taken the strategy of retaining standover heights shut throughout their body dimension vary, so riders can select the attain that matches their driving model or desire. The Stumpjumper affords six sizes to decide on your best attain from – The smallest S1 body is 400mm, the biggest S6 is 530mm, and the sizes in between develop by 25-30mm every.
There are 4 totally different chainstay lengths throughout the six body sizes. The S3 and S4 frames share the identical dimension, as do the S5/S6 frames. Specialised saved the rear ends on the shorter facet, which I’d say is appropriate for a ‘do the whole lot’ path bike.
The Stumpy’s head tube angles are adjustable from an excellent slack 63° to 65.5°, and the seat mast angles differ barely by body dimension however vary from 76.5° to 78°. The BBs experience fairly low at 337mm within the Excessive place or 330mm within the Low (besides the S1 body which sits 3mm decrease).
Mannequin Lineup:
The Stumpjumper 15 Alloy is out there in three full builds and as a frameset. If you happen to drooled over the carbon Stumpys however discovered them a bit past your worth vary, you’ll be comfortable to see the way more attainable fashions within the alloy lineup. Take a look at Specialised’s web site for full construct specs on every mannequin.
Stumpjumper 15 Fox Coil Alloy – $5,500
Stumpjumper 15 Comp Alloy – $4,500
Stumpjumper 15 Alloy – $3,000
Stumpjumper 15 Alloy Frameset – $2,300
specialised.com
