What does the ST bring to the table that the regular Stumpjumper doesn't?
The Specialized Stumpjumper FSR ST Comp Carbon 29 is a short-travel bike with a big name. It has a 130mm fork and 120mm at the rear.
So that’s 20mm less travel than the regular Stumpjumper. It also comes with either 11-speed Shimano or 12-speed SRAM.
There’s also a range of bikes with 27.5in wheels and several women’s models. Most of the options use the same FACT 11M carbon frame, but with different shocks and component specs. Like the Cannondale Habit Carbon 3, Specialized has tuned frame stiffness across the different sizes – apparently it conducted some research and found that taller riders needed extra stiffness, where-as the smaller riders were okay as they were.
Specialized Stumpjumper FSR ST Comp Carbon 29
The carbon frame still sports Specialized’s innovative SWAT door on the downtube, but there’s now a bigger opening and slightly more space inside for all your trail gear. The Stumpy ST also has a Flip Chip in the lower shock mount, which allows you to steepen the head angle by half a degree and raise the BB by around 6mm. It comes pre-set in the low position, so it’s good to go from the off.
Specialized fits a Fox Float DPS Performance shock and Float Rhythm 34 suspension fork to the Stumpy ST. These have a custom Rx Trail Tune, which mean they have a wider operating range and you’re more likely to be in the middle of the dials rather than all at one end.
The 34 fork feels stiff enough on this bike, and it’s relatively easy to set up but we found that Performance series Fox forks can often feel a little harsh when you push them to the limit. Compared to the Specialized Stumpjumper Evo we tested recently, the ST is a lot more supportive and doesn’t wallow as much when you’re sprinting up climbs.
To hit the price point, and get a carbon frame on board, Specialized has had to make some compromises with the specification. This Stumpy ST bike gets SRAM NX Eagle gearing, which works great but it’s heavy, especially the rear cassette and steel chainring. In fact, NX Eagle is about 250g heavier than SRAM GX Eagle, which by our tally is also not far off what you’d save if you upgraded a frame to carbon. You can probably see where we’re going with this – an aluminium framed Stumpy ST with GX Eagle might actually be lighter (and cheaper) than this bike. And there’s proof it would work, because that’s exactly what Giant has done with the Giant Trance 29.
Specialized in-house Roval Traverse 29 rims are tubeless ready and also hookless, but the sidewall is pretty thin and first time out we pinch-flatted the rear tyre. On closer inspection we found we’d dinged the rim quite badly too, and once we took the tyre off, the edge of the rim seemed pretty sharp. We don’t know if this sharp edge caused the puncture, but our advice is to switch to tubeless at the earliest opportunity. The sealed bearing hubs are unbranded but they look the same as those on the Stump Evo and there’s quite a bit of noise in the freehub when rattling downhill.
Compared to the Evo we tested a month ago, the Stumpy ST feels more responsive. It’s nowhere near as long, slack or low, but it’s still rapid on technical trails. On paper the head angle is two degrees steeper than the Giant and Cannondale but it doesn’t feel like it because there’s plenty of length in the frame to get your weight centred. In fact, the Stumpy really puts you in a neutral riding position; ready to attack whatever the terrain throws at you.
This bike isn’t quite as playful as the Giant, but it’s a fun ride that changes direction easily and holds a tight line in loose turns. It climbs really well too. You’re not hanging off the back on the ups, like on the Cannondale and, if you do need to firm thing up, the Pro Pedal lever is within easy reach right underneath the top tube.
The Stumpy ST is a super quick, short-travel trail bike but it has similar issues to the Stumpy Evo we tested last month – it’s hamstrung by the budget parts. We also think the main advantage of having a carbon frame, which is to save weight, is somewhat negated by fitting the heavy NX Eagle drivetrain. You could argue that in the long run you’ve got a great frame to upgrade, which is true, but we think one of the options missing for the extensive Stumpy range is an aluminium framed Stumpy ST with a better build kit.