Review: The Specialized Stumpjumper ST Comp Carbon 29 may be shorter on travel, but it ain’t short on fun

Earlier this year Wil had the pleasure of heading out to Spain for the launch of the new Specialized Stumpjumpers. We’ve now had the Stumpjumper ST Comp Carbon 29 (130/120mm) and Stumpjumper Expert Carbon 29 (150/140mm) back on test to see how they perform on more familiar trails. Here we have Rachel reviewing the shorter travel Stumpjumper ST. Over to Rachel!

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The headline news from Specialized is that for 2019 there are three different Stumpjumper platforms in the range:

• Stumpjumper ST (short travel; 130mm front, 130/120mm rear)
• Stumpjumper (150mm front, 150/140mm rear)
• Stumpjumper EVO (150mm front, 130/140mm rear)

Each platform is available with 29in or 27.5in wheels (the rear travel of each is 10mm less on the 29ers) and in a variety of build options including a women’s specific option (same frame but smaller components, shock tuned for lower weights). To make things a bit easier to keep track of, the women’s specific bikes like the Rhyme and the shorter travel Camber have been subsumed into the Stumpy range.

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The shorter travel Stumpjumper ST is a new name in the Stumpy range, coming in to replace the Camber. Like its predecessor it’s designed to be a trail bike but one that’s a bit quicker and more direct when you’re on the pedals. I regularly ride and reach the limits of my XC full-susser on bigger trails so was keen to see how a more trail orientated short-travel 29er would compare.

There are four models in the Stumpjumper ST range, starting off at £1,700 and going up to £8,000 for the carbon S-Works. The Comp Carbon tested here sells for £3,500, and comes in Small through to X-Large frame sizes, with the 27.5in version offering an X-Small size too.

The Bike

There’s lots of background about the development and attributes of the new Stumpjumper in Wil’s write up of the launch. If you’re a detail person head over there and I’ll try and keep things shorter here.

The ST gets the same new Stumpjumper frame as the longer travel models, but runs a smaller shock and also a shorter 130mm travel fork to give the complete bike a steeper head angle, a lower front end and a lower BB height.

In direct comparison with the outgoing Camber, the Stumpy ST is predictably longer, lower and slacker. Reach on the medium is 435mm (an 8mm increase) and the head angle a whole degree slacker at 67.5^o. Combined, these changes increase the front centre of the bike and total wheelbase by 26mm to a reasonable 1161mm on the medium.

The rear geometry is more similar to before with a 437mm chainstay length and a tidy 75.1^o seat tube angle. There’s a Flip Chip at the lower shock mount, which allows you to change the head angle by 0.5^o and alter the BB height by 6mm. The default position and quoted geometry is in the ‘low’ position so swapping over will make things steeper and higher.

One of the most obvious features of the Stumpjumper is its asymmetric sidearm taken from the Demo DH bike that increases the stiffness of the frame and provides a reinforced loading point for the suspension linkage. In photos it looks quite striking but isn’t that noticeable in the flesh particularly on the dark finish of the Comp Carbon.

A major development for Specialized was to optimise the bike to perform with the latest metric air shocks to achieve a linear feel of the suspension. Each shock is tuned specifically to each of the Stumpy platforms to achieve this ‘Rx Trail Tune’. The ST Comp Carbon gets a Fox Float DPS rear shock with a Fox Float Rhythm 34 up front.

Just like the £8,000 S-Works model, the ST Comp Carbon uses a FACT 11m carbon fibre frame (previously the lower price-point carbon bikes had an alloy rear end). Other features include a beefed up SWAT compartment with a redesigned door to make more room for your snacks and it easier to get to them.

There are permanent cable guide tubes to make re-routing easier too. Assuming this works, it’s a great feature but as I didn’t change any of the cables whilst I had the bike, it’s not one I’ve tested out. The final frame development is a thick contoured chainstay protector to reduce chain slap noise. A small detail in the grand scheme of things but it seems to work surprisingly well.

The drivetrain on the Comp is a mix of Shimano SLX (shifter and cassette) and XT 11-speed (derailleur) with RaceFace Aeffect cranks and a KMC chain. The cranks are a sensible 170mm length given the hefty 39mm BB drop, and I didn’t experience any pedal strike problems even on some pretty lumpy trails.

It’s worth noting that all the 29er Stumpys have a 30t chainring regardless of their travel and whether they run a SRAM cassette with a 50t or a Shimano with a 46t. I found that on less steep and longer rides I’d have preferred a 32t ring as I didn’t need the little gears and spun out a bit at the other end. You may want to change the chainring size to better suit your usual terrain and leg power.

Although the drivetrain mix and Shimano SLX brakes are obviously specced in order for the Comp to meet its price point there was nothing lacking in the performance. In fact, the Shimano SLX brakes were far more reliable than the Guide Rs on the longer-travel Stumpjumper I’ve also been testing.

There’s an X-Fusion Manic dropper post (125mm on Small, 150mm on M-XL sizes), which functioned exactly how a dropper post should function. Bear in mind that if you’re not a fan of the X-Fusion, the bigger 34.9mm seat tube will limit your aftermarket dropper choices unless you use a shim.

The rest of the Comp build is Specialized in-house. There are Roval Traverse Boost wheels with a 29mm inner width alloy rim and Roval branded DT Swiss hubs. The 2.3in Butcher GRID (front) and Purgatory GRID (rear) do look a bit skinny for the job but there’s clearance for up to a 2.8in tyre if you do want something chunkier. Spesh’s 6061 alloy bars are 780mm wide and the Trail stem 45mm on all sizes.

The Ride

Without a single tweak to the fit of the Stumpy ST, I found it Goldilock’s porridge. Although on paper the front end was higher and reach shorter than I’d choose I found both the cockpit and pedalling position really natural. The folks at Specialized have clearly spent a lot of development hours and trail time getting the fit and weight distribution dialled on this bike.

That said, if you think you’re borderline between two sizes, then you’ll likely want to consider the bigger of the two. Given the short seat tube and generous standover clearance, it’s easy to size up if you’re after a bit more reach in the cockpit.

On the trail my first impression was how stable and planted the ST felt – a feel that I’d expect from its bigger brother but not on something which was quick and nimble too. The ST is a really nicely balanced bike and the handling is excellent. I never felt I had to do too much to keep the wheels nicely weighted.

It’s nippy and copes with tight singletrack really well with the stiffness of the frame and front end geometry making the whole bike nicely responsive and making up for the less nippy, bigger wheels. On a couple of occasions I found that the capability of the tyres didn’t match those of the rest of the bike though, with a couple of big wash outs on faster and looser turns. Given how well the 2.6in versions of the same tyres performed on the longer travel Stumpy, I’d solve this by fitting something wider than the stock 2.3in rubber.

With its steep seat angle and stable suspension, the ST gives a really efficient and comfortable pedalling position both on long drags and up steeper kicks, and it will happily cope with all the miles you want to put into it. It doesn’t have that quick and efficient feel or the same acceleration as the XC orientated Epic, but given you’re unlikely to be trying to wheel spin off the start line on a trail ride then it’s not something that you’ll miss. Ignoring any World Cup XC racing ambitions, this bike climbs very well.

For its lesser travel and steeper angles the ST is still an incredibly capable bike on bigger and steeper terrain, which largely boils down to its solid frame and balanced weight distribution. Even riding it in Torridon with my riding mate on the 150mm travel Stumpy I didn’t get that left behind on the descents, certainly not as much as I could have done.

Having said that I did find that the Comp’s descending and trail ability was limited by the difficulty I had getting the suspension performing as I’d like. The lower spec Fox fork and shock just seemed to lack some of the plushness of the RockShox Pike/Deluxe combo that I rode on the longer travel Stumpjumper.

Even after a few months riding I never get to the point where either the shock or fork were riding as I’d like with me either diving right through the whole travel or losing the small-bump sensitivity I was after. Then again, it could have simply been that the ST is so capable that it was copping bigger hits than would usually be suitable for a 120/130mm travel trail bike.

Durability Notes

I had absolutely no durability issues with the ST during its test time although the weather this summer has been uncharacteristically dry so it wasn’t the hardest test for it. Given the frequency that I’ve had to change press-fit BBs on my Epic and Enduro in the past, I will say that the threaded BB on the new Stumpjumper is very much appreciated.

Three Things That Could Be Improved

1. Chunkier tyres to save my gravel rash
2. The entry-level Fox suspension works fine, but it’s not as plush or as controlled as the RockShox combo on the more expensive Expert model
3. The 34.9mm diameter seat post limits aftermarket dropper options unless you use a shim

Three Things We Loved

1. Descending capabilities that are greater than you might expect for a short-travel FS
2. The quick handling and balanced feel: this chassis is solid and has superb weight distribution
3. The out-the-box feel of the cockpit is dialled

Overall

Specialized’s aim with the ST was to design a bike that was nimble, responsive and a good climber, yet capable on the descents. And I think they’ve done a very good job of it.

The ability of the ST makes it much more likely that you’ll push it right to its limits and you’ll start to expect it to pedal as well as an XC bike and match the descending prowess of something much bigger and slacker. Whilst it doesn’t quite go that far you can certain ride it on a wide range of terrain without it ever feeling like the wrong bike.

2019 Specialized Stumpjumper ST Comp Carbon 29

• Frame // FACT 11m Carbon Fibre, 120mm Travel
• Fork // Fox Float Rhythm 34, 51mm offset, 130mm travel
• Shock // Fox Float DPS Performance, Rx Trail Tune
• Hubs // Specialized sealed cartridge bearings, 110x15mm Front & 148x12mm Rear
• Rims // Roval Traverse 29, hookless alloy, 29mm inner width, tubeless ready, 28h
• Tyres // Specialized Butcher GRID 2.3in Front & Purgatory GRID Rear
• Crankset // RaceFace Aeffect, 170mm Arm Length, 30t Chainring
• Rear Mech // Shimano XT, GS cage, 11-speed
• Shifters // Shimano SLX, 11-speed
• Cassette // Shimano SLX, 11-46t
• Brakes // Shimano SLX, 200mm Front & 180mm Rear Rotors
• Stem // Specialized Trail, Forged Alloy, 31.8mm Diameter, 40mm Length
• Bars // Specialized Trail, 7050 Alloy, 31.8mm Diameter, 27mm Rise, 780mm Wide
• Grips // Specialized Sip Grip Half-Waffle Lock-On
• Seatpost // X-Fusion Manic, 150mm
• Saddle // Specialized Body Geometry Phenom Comp, 143mm Width
• Size Tested // Medium
• Sizes Available // Small, Medium, Large, X-Large
• RRP // £3,500

Review Info

Brand:	Specialized
Product:	Stumpjumper ST Comp Carbon 29
From:	Specialized, specialized.com
Price:	£3,500
Tested:	by Rachel Sokal for 2 months

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