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The Specialized Stumpjumper Carbon Comp is an entry-level carbon-framed trail bike aimed at riders who want a capable descending and rewarding climbing machine. Equipped with 140/130mm front/rear travel, it's a solid trail-centre ripper that can handle some rough and steep trails, too.

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Specialized Stumpjumper Carbon Comp - Technical details 

The Stumpjumper Carbon is Specialized’s trail bike offering. Sporting a carbon-fibre frame with 130mm of rear suspension and 140mm upfront, it is naturally a bit lighter than the alloy-framed Stumpjumper. 

The Stumpjumper Carbon is available in the base model Comp spec retailing for £3,900 (pictured here). If you want a better spec, the Expert spec retails at £5,750 which utilises improved suspension and electronic gearing. The Pro spec retails for £7,750 with factory suspension and carbon wheels. The top-spec S-Works model retails at £10,000 –it gets electric everything, carbon everywhere with a fancy S-Works decal on the downtube.

The full carbon frame is built around Specialized’s FSR suspension system which uses a yoke to drive a top-tube-mounted in-line shock. Aside from similar designs on other Specialized bikes such as the Stumpjumper Evo and Levo SL, the Stumpjumper pictured here uses flexstays meaning there is no pivot in the rear triangle. Instead, the carbon seat stays flex a little throughout the travel and are “tuned” to improve ride characteristics. It also saves the weight of some bearings and mounting hardware. 

Specialized_Stumpjumper_Carbon_Comp_7.jpg, by Ty Rutherford

Aside from the suspension, the frame has a whole host of neat features, which shows Specialized has been polishing this design for a while now. Firstly, fully-tubed internal cable routing makes it super easy to route cables through the frame. The quality of the carbon can be seen through the SWAT box which is the in-frame storage solution. This includes a rubberised bag which can be filled with a small pump, tube and other trail-side essentials and tucked into the frame out of the way. 

Specialized_Stumpjumper_Carbon_Comp_8.jpg, by Ty Rutherford

The geometry can be adjusted slightly by using a flip-chip in the rear shock ,which moves the position of the eyelet. From the high- to low position, you’ll see 0.5-degree slacker head angle, a 7mm bottom bracket drop and 0.5-degree slacker seat-tube angle. 

The frame is nicely finished with some protection. This sees a thick rubber guard at the bottom of the downtube and a ridged chainstay protector to keep things quiet. The bottom of the downtube is also heli-taped from the bottom bracket to the head tube to keep those stone chips off the carbon.

Specialized_Stumpjumper_Carbon_Comp_13.jpg, by Ty Rutherford

It also gets a threaded bottom bracket and there's no headset cable routing making the Stumpjumper a little easier to work on for the home mechanic. Rounding off the simplicity is the UDH rear mech hanger, which gives the option to upgrade to the SRAM T-Type transmission if you so wish. 

Specialized Stumpjumper Carbon Comp - Sizing and Geometry 

Specialized offers the Stumpjumper in six sizes ranging from S1 up to S6. Using the size chart this caters for riders from 150cm through to 203cm. At 183cm (6ft), the online size calculator recommended an S4 which seemed a sensible suggestion.

Reach is my usual go-to number to understand the sizing of a bike. For the Stumpjumper, reach numbers range from 410mm up to 535mm across the sizes and there’s a 5mm adjustment between the high and low settings. The S4 comes in with a 475mm reach (in the high setting) which is a little shorter than my perfect number but close enough – especially considering the intended trail duties. 

The head angle of 65.5-degrees (in the high setting) is perhaps a little on the steep side but well within modern geometry expectations. This should provide nimble steering but will feel a little twitchy and less inspiring at high speeds. The short chainstays will also add to this with S1-S4 using 432mm and S5-S6 using 442mm. 

For climbing, seat angle is a key consideration and, at 76.5-degrees, it is a little on the slack side which. This number along with the short chainstays may result in a light front-end during steep climbing. The seat angle also slackens by 0.5-degree in the low setting. 

Specialized Stumpjumper Carbon Comp - Specification 

The Comp spec level is the most budget friendly offering from Specialized. Suspension is taken care of by Fox with a 140mm 34 fork in the Rhythm flavour. It's a basic fork but reliable at this price point. The rear end is handled by a Float DPS performance which will provide a good platform for trail-centre ripping. 

Specialized_Stumpjumper_Carbon_Comp_6.jpg, by Ty Rutherford

The drivetrain is an all-SRAM affair. The 10-52T Eagle cassette and 32T chainring give plenty of range for all but the steepest climbing. The mechanical GX shifter and rear mech are well-proven for good-quality shifting. 

Specialized_Stumpjumper_Carbon_Comp_4.jpg, by Ty Rutherford

SRAM also has the brakes covered with a set of G2RS sporting 200m/180mm front/rear rotors. The X-Fusion Manic dropper post offers 175mm of drop for the S4/S5 sizes, 190mm for S6 and 150-100mm of drop for S1-S3. (Check the spec sheet for specifics). 

Specialized_Stumpjumper_Carbon_Comp_3.jpg, by Ty Rutherford

The finishing kit such as the saddle, bar, wheels and tyres are all from Specialized. The tyres comprise a Butcher upfront with the soft compound and Purgatory out back in the harder compound. It is a sensible tyre combo for trail duties, however, the thin GRID casings may need upgrading if your riding is rocky and square-edged. 

Specialized_Stumpjumper_Carbon_Comp_5.jpg, by Ty Rutherford

A nice little bonus is that the bike comes with a bottle cage and Specialized’s SWAT multi-tool fitted under the cage. This is a handy little multi-tool to have on rides and a nice feature to have come as standard. 

Out of the box, with the SWAT tool but no pedals, the Comp spec bike weighed 13.7kg.

Specialized Stumpjumper Carbon Comp - Setup

Specialized has a large retailer network across the UK and further afield meaning when you buy a bike through its network you’ll get the support to get the bike fully built and set up to what you need.

For me, the usual tweaks to the brake lever, dropper lever and shifter positions along with fitting my own pedals pretty much rounded out the fettling required. 

To get the suspension set up I used Specialized’s set-up website, inputting my height and weight gave me some baseline settings to get things rolling. At 6ft and 95kg, I had 275psi in the rear shock and 99psi in the fork with the rebound a handful of clicks from fully open. 

Specialized Stumpjumper Carbon Comp - Performance 

The Stumpjumper is very much in the trail bike category meaning it should feel spritely and efficient but still handle some rowdy trails. With that in mind, climbing on the Stumpjumper Carbon is productive but not quite as easy as I’d hoped. The light tyres and flexstays give the bike a get-up-and-go feeling where it is easy to accelerate up to speed and, on the climbs, you can feel input of power being rewarded with efficient forward motion. 

2024 specailized stumpjumper.jpg, by Liam Mercer

Unfortunately, I found the seated position to be a little stretched out for my liking. Although the quoted seat angle of 76.5-degrees in the high setting isn’t bad, this is an effective measurement. Due to the frame design the actual seat angle, is quite a bit slacker and the higher you have your seat the more exaggerated this problem becomes. It felt like I was pushing slightly forward on the pedals rather than down which felt like I was recruiting different muscles than usual during pedalling. This rearward weight is compounded with the short chainstays where my weight is more towards the rear axle causing a light front-end on the steep climbs. The trade off, however, is better rear-end grip while climbing. On the topic of climbing, the flexstays do help to combat pedal bob, of which there was very little even with the shock compression fully open. 

Specialized_Stumpjumper_Carbon_Comp_16.jpg, by Ty Rutherford

Now on to the fun bits: descending on the Stumpjumper is a real hoot. The bike is light, and agile and carries speed well, making it fun to flick between lines and find little trail gaps. Thanks to the flexstays, it has great pop making it easy to get in the air and it rewards pumping any mid-trail downsides to generate speed. The frame feels well-built and runs silently over the rough stuff thanks to well-designed chain stay protection and internal cable routing tubes.

Under braking, I found the rear end to stiffen up which results in the rear wheel feeling a little skittish and braking traction in the rough is compromised a bit. This is much less noticeable on smooth trail sections and with some sneaky line choice, the problem is fairly easily mitigated. There was plenty of ramp-up at the end of the travel, I didn’t experience any harsh bottom outs or change any settings on the rear shock from the suggested baseline settings I used. 

Specialized_Stumpjumper_Carbon_Comp_14.jpg, by Ty Rutherford

The Fox 34 Rhythm fork, on the other hand, was a bit of a letdown. I would go as far as to say it was my biggest sticking point of the whole bike. The fork lacked support through the mid-stroke and bottom-out resistance was poor leading to some very harsh bottom-outs on the more rowdy trails. I should add here that, on smoother, flow trails, this was not an issue but successive big hits and square edges are where this fork fell short. To combat this I had to strike a balance between small-bump compliance and support finally landing on an extra 20psi (20%), which unfortunately compromised front-end grip and compliance but did stop the worst of the bottom-outs. Unfortunately, you cannot upgrade the Rhythm damper so you’d need to buy a new fork to improve front-end performance. 

Specialized_Stumpjumper_Carbon_Comp_15.jpg, by Ty Rutherford

As for the rest of the spec, the SRAM G2 four-piston brakes were impressively powerful and a real standout on the bike – super confidence-inspiring to brake that bit later into the corner. The sticky compound Butcher front tyre gave plenty of grip and I was impressed with the braking on offer from the reasonably minimalistic Purgatory rear tyre. The thin GRID casings have held up well to a range of roots, rocks and hard cornering but you may consider upgrading to slightly thicker casings such as GRID Trail if you’re riding a lot of pointy rocks. The rest of the finishing kit is all super functional and gave me no reason to want to upgrade other than personal preference. I particularly liked the OEM Specialized grips which are the perfect diameter and impressively comfortable to run. 

My last little gripe is the dropper post travel on the S4. I had an awful lot of seatpost out the top of the seat tube and feel the 175mm travel could have been specced with a 190mm drop on the S4/S5 (this same as the S6). 

Specialized_Stumpjumper_Carbon_Comp_11.jpg, by Ty Rutherford

Specialized Stumpjumper Carbon Comp - Verdict

Retailing at £3,900, the Stumpjumper Carbon Comp provides a solid platform for future upgrades as parts wear out and money allows. It's a well-put-together, high-quality item and you’ll be in the safety of Specialized’s solid warranty programme. Another option worth considering is the YT Izzo which is also a 130mm rear travel bike, has a carbon frame and is designed to be a trail ripper. The Izzo in the Core 3 flavour comes in slightly more expensive at £4,300 but the Performance Elite fox suspension is a significant upgrade making the extra £400 easily justified. Even on the lower Core 2 spec, the Fox suspension is an improvement over the Stumpjumper and, although the drivetrain is lower spec on the Core 2, it retails at £3,200.

The Specialized Stumpjumper Carbon Comp is an entry-level trail bike. The stiff carbon frame, relatively fast rolling tyres and efficient suspension make this bike a handy climber, however, the slacker seat angle does detract a little from its full potential. During descending, the geometry gives the bike a playful nature and the tuned flexstays give the bike a lively feel that inspires confidence during quick direction changes and little trail gaps. Overall, the spec is excellent for the bike's intentions with the brakes and tyres being standout features. However, the fork is the biggest sticking point on this build which restricts the full riding experience. It's an excellent little trail ripper but consider the next spec up (Expert) or an extra outlay for upgrading the fork if you’re riding anything more than smooth flow trails.

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