2018 Specialized Stumpjumper S-Works
First Impressions/Release

Specialized Announces Three New Stumpjumpers

Words AJ Barlas
Photos All Images Harookz/Specialized unless noted
Date Apr 17, 2018

The Specialized Stumpjumper is one of the most iconic mountain bikes ever. The Stumpy has been a staple in the Specialized lineup since 1981. Over those 37 years, the bike has gone through quite the evolution with the most recent pushing how short rear stays could be on 29ers and the integration of storage inside the main frame thanks to the SWAT door. 

Despite brining these innovations forward the most recent version has grown a little old in the tooth; both the suspension and geometry had some catching up to do. Those elements and more were tackled with the 2018 Stumpjumper in a push to create what Specialized is labelling the "ultimate trail bike.” 

Specialized Stumpjumper Expert 29

The 2018 Stumpy no longer needs to hide in the shadows.


The New Stumpjumper Models

For 2018 there isn't just one but three new Stumpjumpers; The Stumpjumper ST (Short Travel), the Stumpjumper, and the Stumpjumper Evo. The ST replaces the Camber and given the cross-over of the Camber and Specialized’s desire to create the ultimate trail bike, it fits in well as the shorter legged Stumpy. The Evo is also back in the lineup as the aggressive rider's trail bike, with some interesting new developments. The bikes are available with 27.5 or 29-inch wheels and the Stumpy and Stumpy ST are available in both carbon and alloy materials, in male and female specific packages.* The Evo is only available in a single alloy option for the time being.

*The regular female specific Stumpy is only available with a 27.5-inch wheel


The new bikes range in price from 1,850 USD for the short travel base model to 9,500 USD for the S-Works. There is a frame only option and if you go this route you will be committing to the S-Works; it will retail for 3,200 USD. The Evo will only be available in the Comp alloy initially and will retail for 3,600 USD. Pricing is the same regardless of wheel size, suspension travel option, or men’s/women’s models.

2018 Stumpjumper Pricing

  • S-Works: 9,500 USD / 11,269 CAD
  • S-Works Frame 3,200 USD* 
  • Expert 5,500 USD / 6,659 CAD
  • Comp Carbon 4,200 USD / 5,119 CAD
  • Comp EVO 3,600 USD* 
  • Comp 3,000 USD / 3,889 CAD 
  • ST base 1,850 USD / 2,659 CAD  (base model only available in ST configuration)

*No Canadian pricing available at the time of release. 

Frame Design

Perhaps the most notable feature of the 2018 Stumpjumper is frame design. Similar to the Demo, Specialized has incorporated a single-sided structure they refer to as the “sidearm.” The sidearm, found on the driveside of the bike, goes around the shock and connects the forward shock mount down to the seat tube pivot. This connection is said to provide a number of benefits including better trail feel thanks to the improved connection between a rider's contact points and the wheels. Trail feel was a key feature for Stumpy design team.

Specialized Stumpjumper sidearm detail, non-driveside

Non-driveside sidearm detail

Specialized Stumpjumper sidearm detail, driveside

Driveside sidearm detail

The one-sided structure allows for optimal shock placement while keeping width and weight down. A bonus is better shock access. Perhaps the least obvious reason behind the side-arm and how it’s connected is in relation to the suspension. 

Frame engineer, Jason McDonald noted that when bottoming out the rear suspension on the old Stumpy the distance between the front shock mount and the main pivot grew by 3mm. The increased stiffness of the new design reduces that growth to only 0.3mm, one tenth the previous flex. 

The significance of this is that those “extra” millimetres of travel at the bottom end created an unpredictable and undamped feel at the end of stroke as the force was transferred through the frame and released. Minimizing the flex in this area when the suspension is active is said to improve suspension performance over bumps, not just at the extreme end, providing a more reliable and positive feel to the suspension and improving the overall ride quality of the frame. 

Specialized Stumpjumper sidearm detail

Specialized says that connecting the sidearm from the front shock mount to the main pivot at the seat tube improves the connection between the rider and the bike while reducing frame flex in this area. 

Ride feel and frame flex or stiffness go together like peas in a pod and the development team spent a lot of time working on this with the new Stumpy. During testing of the previous model the team noticed that certain sizes, particularly the larger end of the scale, didn’t track as well as they would have liked. To improve the connection between the rider and the ground they needed to work on this and in the process a new test was developed that enabled them to quantify what was happening to the frame and what they were feeling when riding. 

Armed with this new testing process, the team now had a benchmark that they wanted to aim for. Within a range they found the bikes to feel and ride great, too stiff and the frame would contain added weight and a dead feeling, too soft and the bike wouldn’t track as desired. After testing things too far toward the stiff end of the range, they pulled back a little to arrive at what they deem to be the sweet spot for trail bike feel. A bike the team feels is lively while tracking well. 

Once the sweet spot was identified the team moved to the large and extra large sized frames, over-wrapping the current model with added carbon in order to test it out. Although the two larger sizes were most in need of the improvements, all frame sizes ended up stiffer than the outgoing model. The larger sizes simply required more work for the team. The shaping of the tubing and the layup painstakingly analyzed in an effort to achieve optimal feel. We were told rear end stiffness across the size range increased approximately 8%, yet is still 100g lighter. All frames make better use of the carbon layup, with Specialized claiming it’s 20% more efficient and is one of the lightest trail bike frames on the market.  

Stumpjumper test frame with overwraps of carbon material.

An example of a test frame used during the search for the right flex on the trail. Overwraps of extra carbon material are added to certain areas of the frame to see how it affects the flex of the frame when riding. Photo: AJ Barlas

Stumpjumper BB cutouts

The increased efficiency of the carbon material is visible here. On the right, a cutout from the new Stumpjumper and the old on the left. The new one is cleaner and uses less material, but is still claimed to be stronger. Photo: AJ Barlas

The 2018 Stumpjumper contains a regular 73mm threaded BB in place of the PF30 used in its predecessor. When questioned on the move Specialized stated that press-fit bottom brackets are no longer a weight advantage with the cranks now available. There’s also a new chainstay protector that looks a little funky, sounds pretty quirky, but in reality, works phenomenally well. Who would have thought that strategically placed rises in the protector could cut down the noise so much, but it works and this is the quietest bike I've ridden to date.

The team have also improved the SWAT door and made the storage space 20% bigger in the process. Cable routing has been improved and the team went to “great lengths to make it easy to work with.” When fitting a cable it goes into the headtube and comes out where it needs to – whether by the rear brake or rear derailleur. There is no need to fish cables through sections of the frame. The new Stumpy also features a flip chip to adjust the bike's geometry – with the low setting sitting 6mm lower and providing an approximately 0.5-degree slacker headtube angle. There’s also room for up to 3.0-inch tires on both the 27.5 and 29-inch wheeled bikes.  


Specialized Stumpjumper Chainstay protector

The Specialized Stumpjumper's feature a newly developed chainstay protector that drastically improves noise reduction. This is one very quiet bike on the trail. 

New 160mm Specialized dropper post

With the seat tubes getting shorter they've also developed a longer travel dropper post to work with the new bikes. It features 160mm of travel, but no wu on this one (like the Enduro). 

Specialized Stumpjumper new chainguide

Specialized also released this new chainguide. No tool is required to open and close the guide, making it easy to work with. 

Suspension Design

For the new Stumpjumper, Specialized noted that the frame and suspension teams worked together more closely than ever before. Chance Ferro, head of the Rider Experience, or RX program, was involved in the development of the frame from early in the process and says that this early involvement allowed the team to focus on how the suspension is designed into the new bike from the beginning. Looking at how the design could improve the way the shock is driven and working on a leverage ratio that works well with the shock, rather than attempting to fit it to what they were trying to get after the fact, are highlights mentioned with the process.

The new Stumpjumpers are said to provide more support from the spring, an element that was a focus during the development process. They also provide a lighter ride off the top while giving more support in the mid-stroke thanks to a larger negative spring. This change doesn't play well with Autosag and it is no longer offered. Instead we see the range fitted with either a RockShox Deluxe, Fox DPS or DPX2, or X-Fusion 02 Pro RL depending on the model. All shocks are, however, custom tuned with the new RX Trail Tune developed for the bike and there will also be an app available to assist riders with initial setup.


Testing the offset shock layout. Photo: Colin Belisle/Specialized

Testing the offset shock layout. Photo: Colin Belisle/Specialized

An early sample of the offset yoke on the Stumpjumper

A sample of the offset yoke used with the new frames.

With coil sprung shocks seen as the gold standard, Specialized worked hard in the development of the RX tune for the Stumpjumpers to approximate a coil as much as possible. The wheel and spring rates on the new Stumpy present more consistent curves than previously and are said to work well with coil or air shocks thanks to the kinematics developed and the tune of the air shocks. The team also mentioned that there are already some coil sprung shock tunes completed for the bike that will be available for consumers that wish to go this route. 

Geometry and Sizing Philosophy

As any bike brand worth their salt would do today, Specialized dedicated testing time to experimenting with the extremes in geometry during the development of the 2018 Stumpys. In the end, they found a number of benefits and downfalls, and tailored the bike to suit what it’s designed to do; ride trail really well, up and down. The outcome of the testing process has resulted in two geometry concepts for the Stumpy. 

Despite looking at the numbers holistically, the team arrived at the now cliché longer and slacker trend, but passed on lower. A desire to remove the need for a stem any longer than 50mm helped steer the direction of the longer front centre. Seattubes were also shortened in an effort to allow riders more choice in sizing and longer droppers have been fitted to a number of frame sizes with Specialized’s new and improved 160mm travel dropper. These attributes are noticeable across all three bikes but differ where the bike needs to be tailored more specifically. 

2018 Specialized Stumpjumper ST 29 Geometry

Frame size: Small Medium Large Extra-Large
Reach: 415mm 435mm 455mm 480mm
Top Tube (Horizontal): 569mm 592mm 624mm 657mm
Stack: 607mm 607mm 635mm 649mm
Seat Tube Length: 380mm 410mm 455mm 505mm
Head Angle: 67.5º
Seat Tube Angle (Effective): 75.8º 75.5º 75.1º 74.7º
BB Drop: 39mm
Chainstay Length: 437mm
Front Center (mm): 707mm 727mm 758mm 789mm
Wheelbase: 1,141mm 1,161mm 1,192mm 1,223mm
Fork Offset: 51mm
Trail: 99mm

2018 Specialized Stumpjumper ST 27.5 Geometry

Frame size: Small Medium Large Extra-Large
Reach: 425mm 444mm 465mm 490mm
Top Tube (Horizontal): 568mm 591mm 624mm 657mm
Stack: 586mm 590mm 618mm 631mm
Seat Tube Length: 380mm 410mm 455mm 505mm
Head Angle: 66.5º
Seat Tube Angle (Effective): 76.3º 76º 75.6º 75.2º
BB Drop: 28mm
Chainstay Length: 432mm
Front Center (mm): 718mm 739mm 772mm 803mm
Wheelbase: 1,149mm 1,170mm 1,203mm 1,234mm
Fork Offset: 46mm
Trail: 103mm

With the Stumpy ST taking up the place of the Camber, it was important for it to carry over those snappy, quick handling characteristics, while the regular Stumpjumper aims straight down the middle of climb and trail characteristics and needed to be more stable at speed. The Evo is definitely the black sheep with more focus on descending and more extreme numbers to boot. Nevertheless, the bike is aimed squarely at the trail rider and it needs to climb comfortably; a key attribute that ultimately resulted in the team pulling back from some of the geometry extremes tested. One attribute that stuck with the Evo was a shorter offset fork. With a slack 63.5-degree headangle the Evo was found to work better with a custom 44mm offset fork on the 29er and a 37mm offset on the 27.5.


2018 Specialized Stumpjumper 29 Geometry

Frame size: Small Medium Large Extra-Large
Reach: 405mm 425mm 445mm 470mm
Top Tube (Horizontal): 572mm 595mm 628mm 662mm
Stack: 614mm 614mm 641mm 656mm
Seat Tube Length: 380mm 410mm 455mm 505mm
Head Angle: 66.5º
Seat Tube Angle (Effective): 74.8º 74.5º 74.1º 73.7º
BB Drop: 33mm
Chainstay Length: 437mm
Front Center (mm): 714mm 734mm 766mm 797mm
Wheelbase: 1,149mm 1,169mm 1,201mm 1,232mm
Fork Offset: 51mm
Trail: 107mm

2018 Specialized Stumpjumper 27.5 Geometry

Frame size: Small Medium Large Extra-Large
Reach: 415mm 435mm 455mm 480mm
Top Tube (Horizontal): 570mm 595mm 627mm 660mm
Stack: 592mm 596mm 623mm 637mm
Seat Tube Length: 380mm 410mm 455mm 505mm
Head Angle: 65.5º
Seat Tube Angle (Effective): 75.3º 75º 74.6º 74.2º
BB Drop: 21mm
Chainstay Length: 432mm
Front Center (mm): 726mm 748mm 780mm 812mm
Wheelbase: 1,157mm 1,179mm 1,212mm 1,243mm
Fork Offset: 46mm
Trail: 112mm

Compared to the other Stumpjumpers, the Evo has a longer reach, slacker head angle, shorter seat and headtube length respective to each size, and longer chainstays, relative to each wheel size. Speaking of frame size, there isn’t really one with the Evo, at least not in the traditional sense. The sizing is labelled as S2 – the smaller of the two – and S3. Rather than focus on more traditional sizing via seat tube lengths the Evo buyer will need to look at the geometry as a whole to decide which size suits their needs best. 

2018 Specialized Stumpjumper Evo 29 Geometry

Frame size: S2 S3
Reach: 445mm 475mm
Top Tube (Horizontal): 599mm 635mm
Stack: 619mm 623mm
Seat Tube Length: 400mm 450mm
Head Angle: 63.5º
Seat Tube Angle (Effective): 76º 75.6º
BB Drop: 47mm
Chainstay Length: 443mm
Front Center (mm): 781mm 813mm
Wheelbase: 1,220mm 1,252mm
Fork Offset: 44mm
Trail: 138mm

2018 Specialized Stumpjumper Evo 27.5 Geometry

Frame size: S2 S3
Reach: 465mm 490mm
Top Tube (Horizontal): 615mm 647mm
Stack: 601mm 610mm
Seat Tube Length: 400mm 450mm
Head Angle: 63.5º
Seat Tube Angle (Effective): 76º 75.6º
BB Drop: 33mm
Chainstay Length: 440mm
Front Center (mm): 790mm 820mm
Wheelbase: 1,228mm 1,258mm
Fork Offset: 37mm
Trail: 137mm

In a nutshell, the geometry of the three new Stumpjumpers is focused on aligning with what a particular rider desires from their trail bike. Snappy and quick-handling, a confident all-rounder or the more aggressive, Specialized are aiming to appease the range of trail riders out there with the new bikes. 


Aj riding climbing the 2018 Specialized Stumpjumper ST 29 in Spain

Initial Riding Impressions

These are early days and I didn't spend enough time on any of the three of the new bikes. There was however enough time to confidently say that while each Stumpjumper serves its own purpose, the bikes share character traits that make it obvious they belong to the same family. Also of note are the improvements across the line, compared to previous iterations. The improvements to the bike's suspension are significant and quickly noticed, providing a more predictable and stable feel compared to the predecessor. All three of the bikes were also among the quietest I have experienced, with the new chainstay protector design having a notable influence.

Having only the time to ride one wheel size, that is what these impressions focus on for each model. All models were tested with the flip-chip in the low-setting

The Stumpjumper Short Travel (ST)

The Stumpy ST features 120mm of rear travel and 130mm front in the 29-inch wheeled version while the 27.5-inch wheel bumps the travel in the rear 10mm to 130mm. Its geometry, as one might assume, is a little steeper than the regular Stumpy and it’s clear on the trail. The geo differs slightly between the wheel sizes too with the 27.5 featuring a slacker headtube but steeper seattube angle. As mentioned, this is the replacement for the Camber, so if that was a bike of interest at any point, the Stumpy ST may be your new poster boy. 

Snappy and quick handling are two very appropriate terms to convey how the ST rides, but where it differs to some short travel 29ers is that despite these characteristics, the bike is remarkably stable. Riding blind through rock gardens, at times on less than preferable lines, the bike exhibited a calmness that allows the rider to stay composed and on top of the situation at hand. 

Aj riding the 2018 Specialized Stumpjumper ST 29 in Spain
AJ Barlas on the back wheel of the 2018 Specialized Stumpjumper ST 29 in Spain

The short travel whippet makes for a super enjoyable ride, as is clear…

AJ Barlas on the new 2018 Specialized Stumpjumper ST 29 in Spain

The bike remained surprisingly well put in rocky terrain for such a short travel whip.

Pushing into the bike was met with a positive response, yet there were no sharp or harsh points noticed throughout the travel. Even bracing for impact after a huck gone wrong, landing flat in loose baby-head rock, was surprisingly smooth and the bike continued tracking remarkably well all the way through the corner that followed. The ST provided a quiet and comfortable ride that felt at home from the outset with a very natural “in the bike” feel, and despite it being targeted toward the rider looking to climb more, don’t discount its capabilities when the trail goes down.

The Stumpjumper ST is available in a female-specific package with a focus on the touch points – things like saddle and grips – being tailored to female riders and a suspension tune that is lighter than on the unisex models. Specialized notes this is to provide a more comfortable ride for the lady shredders among us.  

The Stumpjumper

The Stumpy fitted with 27.5-inch wheels presents 150mm of travel front and rear while the 29-inch version has 140mm rear and 150mm front. The bike features a slacker head and seat tube angle than the short travel option, with the goal of increased stability for this all-around package. As with the ST, the smaller-wheeled Stumpy has a slacker head angle and steeper seat tube angle. Of note is that the longer travel Stumpjumper's will be spec’d with 2.6-inch tires while the ST will come with 2.3-inch treads. 

The regular Stumpy felt a little taller from the outset and as a result, it was more comfortable running a little deeper in its travel with about 33% sag. This was primarily the result of chasing the feeling of being in the bike that was found on the short travel, which features an extra 6mm of static BB drop. The ST features a 39mm BB drop while the Stumpy is set to 33mm. The bike rode well even with the setup running a little deeper and during the short time on the Stumpjumper there were no negative traits found with the deeper sag setting. 

AJ Barlas riding the 2018 Specialized Stumpjumper 29 in Spain
AJ Barlas climbing the 2018 Specialized Stumpjumper 29 in Spain

The suspension on the Stumpjumper remains relatively quiet, even when hammering out of the saddle.

AJ Barlas riding the new 2018 Specialized Stumpjumper 29 in Spain

It's a bike that inspired confidence, allowing the rider to focus on how they want to ride rather than just making it down. 

At speed and in rough terrain the Stumpjumper rode with more confidence than the ST, which is to be expected. It still exhibits a spritely personality and is very easy to manoeuvre but it’s calmer feeling thanks to the relaxed geometry and extra travel. There’s less need to be precise with wheel placement. Flying off obstacles and riding blind into trails was less of a worry on the regular Stumpy and I was able to get away with more. Steering was stable and easily managed with the bike tracking very well in varied terrain.

Use of the travel at the rear of the bike, like on the ST, was consistent and efficient, with no harshness or dead spots to speak of. The mid-stroke provided ample support when mashing on the pedals and contributed to the lively attitude the bike exhibited. The bike was run with the rear shock left open with little need seen to adjust, even on road climbs. The team really has made big improvements to the suspension over its predecessor resulting in a far more composed bike in a variety of terrain. 

The Stumpjumper is also available in a number of female-specific builds with touch points and suspension tunes being the key differentiators. Unlike the ST, the women’s Stumpy is only available in the 27.5-inch wheel size. 

The Stumpjumper Evo

Yes, it’s back and it’s an interesting bike, to say the least. The 2018 Stumpjumper Evo features the same travel as the appropriate wheelsize brothers and sisters, only the geometry has been pushed further. The development team discovered some attributes at the extreme end of the spectrum that were promising and dialling back those extremes slightly – less than with the other two models – resulted in the new Stumpy Evo. The Evo is what Specialized feels is the best balance in order to remain on target as a trail bike but with some serious capabilities.


AJ Barlas riding the 2018 Specialized Stumpjumper Evo 29 in Spain

Out of the gate and on a brand new trail the Evo begged for speed and to be sent into the air. Stability far outshone the other two Stumpys thanks to the longer wheelbase and specifically, longer rear end, which shifted the rider’s mass to a more central position between the wheels. This change in weight distribution would have been more pronounced had there been an S4 available, because at 191cm tall, the S3’s 475mm reach is on the short side. This is fine since I’m toward the top end of the bell curve targeted with the two sizes.

Nevertheless, the bike demands confidence and when provided with a commanding ride, the result was fantastic. Pushing the Stumpy Evo harder into corners and obstacles only resulted in it wanting more, and a shit-eating grin on the riders face. Tracking was excellent and proven by the bike's composure in choppy corners, with relaxed and quiet steering; a testament to the shorter 44mm offset combined with the 63.5-degree headangle. Despite the less traditional shape of the bike, there were no issues swinging it through the tighter sections of trail experienced.

The amount of time spent on the Evo, like the rest, wasn’t enough to make any bold claims, however, it's definitely worth the attention of anyone with a desire to ride aggressively or try something with a slightly more radical geometry. It would be great to see an S4 sooner than later and with a reach in the area of 500mm+ because I want to spend more time with this bad girl. At 3,600 USD, this bike is a killer package too.

Within the Evo line, the 27.5 wheeled model features a longer front centre rather than the slacker head angle common with the smaller wheeled option of a model. The team at Specialized found this change better transferred the ride feel across the two sizes as opposed to making the headangle even slacker.  

The 2018 Stumpjumper ST and Stumpjumper are available now and the Evo will be available in late June/early July. Check out the Specialized website for more details on the bikes.  



Comments

LoamtoHome
0
Jerry Willows  - April 16, 2018, 10:24 p.m.

I believe the new SJ is a 2019 model and not a 2018 as noted in other publications.

Reply

zigak
0
ZigaK  - April 17, 2018, 1:20 a.m.

I really like where big S is pushing the press fit BB.

Reply

xy9ine
+3 mike James Vasilyev AJ Barlas
Perry Schebel  - April 17, 2018, 6:41 a.m.

impressively aggressive numbers on the evo. and in aluminium only - at a reasonable price point. definitely the most interesting bike of the lot.

Reply

fartymarty
0
fartymarty  - April 17, 2018, 8:50 a.m.

I predict a lot of very positive reviews for the Evo.  It looks like a great ride.

Reply

DBone95
0
Darryl Chereshkoff  - April 17, 2018, 7:37 a.m.

Love the cable routing, threaded BB and design, but that rear tire clearance to the seat stay brace looks like a rock and mud catcher...... other than that, it ticks all my boxes.

Reply

morgan-heater
0
Morgan Heater  - April 17, 2018, 8:13 a.m.

If you guys need proof readers, I'll read for carbon wheels.

Reply

Endur-Bro
-1 Darryl Chereshkoff
Endur-Bro  - April 17, 2018, 10:40 a.m.

Evo models are really the only news worthy item in this press junket.  Once a carb0n frame comes out regular Stumpy models will be undesirable.

Reply

tashi
0
tashi  - April 21, 2018, 2 p.m.

Speak for yourself, I’m certainly not the only serious rider out there who likes his hard earned cash more than he likes the joy of riding carbon.  I don’t “desire” a carbon bike in the least.

Reply

DemonMike
0
mike  - April 19, 2018, 7:39 p.m.

EVO model looks killer in the raw finish , I,ll take a 29er please

Reply

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