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Specialized S-Works Stumpjumper ST 29 review

Fast and fun ripper for smoother, mellower trails

Our rating 
3.5 out of 5 star rating 3.5
Specialized S-Works Stumpjumper ST 29

Our review

While hard to recommend as a complete package, this Stumpy still rips smoother trails to pieces
Pros: Corners like an absolute demon and feels super-reactive; flickable and fun any time there’s even a hint of getting airborne
Cons: Beats you up at both ends over rough, repeated stutter-bumps and holes; Specialized’s latest GRIPTON tyres feel sketchy and vague
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There are a heap of different Stumpjumpers available this year, in both wheel sizes, from the slacked-out, progressive EVO bikes to the snappy Short Travel models. The S-Works is the ultimate (and most expensive) ST version.


Specialized S-Works Stumpjumper ST 29 frame

Specialized has crammed the tech into its latest carbon fibre frame, but also ditched proprietary features for simpler repairs and less maintenance.

Stumpy shocks now use standard eye-to-eye measurements and mounts, and the bottom bracket (BB) shells have reverted from press-fit to threaded.

The distinctive frame uses a radical-looking one-sided design, backed by R&D claiming optimal stiffness and weight saving. It looks fresh, but the geometry is more conservative than radical, with less reach than others similar bikes.

The brand’s proven Horst link FSR design allows deep suspension tunability, and a padded rubber bumper on the driveside keeps the ST quiet and protects the stay.

With almost too many chassis details to go into, the flip-open ‘SWAT’ compartment in the down tube stands out as especially good.

Specialized S-Works Stumpjumper ST 29 kit

The S-Works bike gets Specialized’s own Roval Traverse SL carbon hoops, with 30mm-wide rims and DT Swiss hubs. With just 24 spokes at the front and 28 at the rear, these are a light wheelset, but aren’t the stiffest on the trail.

The lightweight, 50mm Syntace stem is nice, but I swapped it for the 30mm version to improve steering reactiveness in tandem with the longer-offset (51mm) Fox 34 FIT4 fork.

A full SRAM XX1 drivetrain adds some bling and shifts smoothly, but the BB, oddly, doesn’t house an oversized DUB axle, which provides noticeably stiffer and more efficient cranking elsewhere.

Specialized S-Works Stumpjumper ST 29 ride impressions

Specialized S-Works Stumpjumper ST 29
Specialized’s carbon wheels are light, but the 24 front and 28 rear spokes won’t work well for the heaviest riders.
Mick Kirkman

With a 1,192mm wheelbase, the Stumpy ST is relatively short. This adds nimbleness, but also makes it less planted at speed on rough tracks. At times, I also felt a bit cramped on the large frame – which isn’t ideal at 5ft 9in.

Advertised as a poppier rig with 120/130mm of travel, more precision is to be expected. This is fine, as long as it brings with it sharp pedalling, agile climbing and a rapid ride. Sadly, the £8k+ S-Works bike only partially delivers on these.

First off, the relatively narrow (2.3in), GRIPTON-compound own-brand tyres hinder its downhill and cornering prowess. When leaned over they’re unsupportive, so you can’t charge.

This is at least cheap to fix, but in terms of pure urgency, the ST simply doesn’t feel as snappy and fast as expected under power – certainly for a super-light 120mm 29er. The Scott Genius 900 trounces it in terms of climbing ability and acceleration, even with 30mm more bounce.

This reduced zip is down to less response and drive under power from the rear end, with the Fox shock feeling soggy in the mid stroke. Even with less travel, it’s only the Stumpy’s low weight that speeds its progress.

Despite the soft suspension (I ran 270psi and ‘trail mode’ to tighten up the ride), other 120mm bikes feel smoother and more planted. The sharp ST hammers your hands and feet at speed, and definitely doesn’t excel on seriously beaten-up trails.

If this all sounds negative, that’s because it is. But – and it’s a big but – everyone who rode it found the Stumpy to be a grin-inducing revelation on certain trails.

On smoother dirt and through berms and rollers on mellow gradients, it was almost impossible for other bikes to keep up with. It’s hard to explain, but this thing absolutely rips corners and blazes down easier trails, smashing through berms and firing out the other end.

The bike pops and pings off jump faces and edges just for fun and with lightning speed. For advanced riders, it’s like a dual slalom rig on steroids, but you’ll need to think long and hard about what you actually need a bike to do. Yes, this thing can be a proper little beast, but anywhere with chunkier terrain and it’ll fall short.

Specialized S-Works Stumpjumper ST 29
The hidden down tube SWAT box is a brilliant stash pot for kit on shorter rides.
Mick Kirkman

Specialized S-Works Stumpjumper ST 29 geometry

  • Seat angle: 69.3 degrees
  • Head angle: 66.5 degrees
  • Chainstay: 17.2in / 43.7cm
  • Seat tube: 17.91in / 45.5cm
  • Top tube: 24.72in / 62.8cm
  • Bottom bracket height: 13.43in / 34.1cm
  • Wheelbase: 47.28in / 1,201mm

Product Specifications


Price AUD $12250.00GBP £8250.00USD $8920.00
Weight 12.4kg (L) – without pedals
Brand Specialized


Available sizes S, M, L, XL
Headset Specialized
Tyres Specialized Butcher GRID GRIPTON 29x2.3in (f), Specialized Purgatory GRID GRIPTON 29x2.3in (r)
Stem Syntace MegaForce2, 50mm
Shifter SRAM XX1 Eagle
Seatpost Specialized Command Post IRcc, 160mm
Saddle Specialized Phenom Expert
Rear shock Fox Float DPS Factory EVOL RX
Rear derailleur SRAM XX1 Eagle (1x12)
Handlebar Specialized Trail carbon, 780mm
Bottom bracket SRAM GXP
Grips/Tape Specialized SIP
Frame FACT 11m carbon fibre, 120mm (4.7in) travel
Fork Fox Float 34 Factory FIT4, 130mm (5.1in) travel
Cranks SRAM XX1 Eagle carbon, 32t
Chain SRAM XX1 Eagle
Cassette SRAM X01 Eagle, 10-50t
Brakes SRAM Guide RSC S4, 200/180mm rotors
Wheels Roval Traverse SL, carbon