The 2021 Specialized Stumpjumper is a brand new and refreshed bike with updated geometry and on the carbon models, a new suspension platform using flex stays instead of a lower pivot in the chainstays. In this spec its an incredible all rounder, the price is steep though, but I guess you do get SWAT....
This bike is the carbon Stumpjumper Expert with it's new flex stays. Where last year, and previous Stumpjumpers, they used the brand’s FSR horst link, the new carbon bikes use seat stays with a small amount of flex rather than a lower pivot on the chainstay. The alloy bikes don’t get the flex stays though, those bikes keep the horst link normally associated with the brand's FSR platform.
This bike I had in on test is the S3, which equates to a Medium. S sizing, in conjunction with shorter seat tubes, allows prospective riders to choose between three sizes of bike, technically I could ride and S2, an S3 and an S4 but I settled on the middle of those three. It does mean that riders do need to be aware of what geometry figures might suit them, but that’s nothing a quick sit on a demo bike or a study of geometry charts won't sort out.
Our bike is the Expert spec which costs £4,750. This bike gets a Fox Float 34 Performance Elite fork, a Fox Float DPS Performance Elite shock, SRAM G2 RSC 4-pot brakes, SRAM X01 Eagle, an X-Fusion Manic dropper post and a smattering of Specialized parts elsewhere.
The new range of Stumpjumpers are 29er only and all have 130mm of rear travel, paired with a 140mm fork. The wheels and tyres are all Specialized branded, there are Roval wheels with a 29mm internal diameter, 2.3" Specialized Grid tyres (Butcher front and a Purgatory at the rear) and 35mm diameter bars and stem.
Getting out on the trails and its immediately apparent that the bike pedals well. I spent a fair bit of time aboard the last generation Stumpjumper and this one is worlds apart in terms of pedalling efficiency. This has large amounts to do with improved geometry including that 76 degree effective seat angle, putting the rider in a more efficient position. We'd personally like to see it even steeper, but this is definitely a step in the right direction. The suspension still bobs a little when pedalling hard, but there are options on the Fox shock to flip the compression to Trail or Closed to lock the shock and accommodate for this. It's a trade-off for an active and engaging suspension platform, providing grip both uphill and downhill.
I rode the bike with the flip-chip in high and low, opting to keep it in low most of the time. My local riding is still quite a bit of winch and plummet, up and down forest singletrack and as the bike pedals so well I chose to ride the bike in the position which provided the slackest head angle and lowest bottom bracket point. In the low position on this S3 the Stumpjumper gets a reach of 450mm, a head angle of 65 degrees, an effective seat tube angle of 76 degrees and an effective top tube of 605mm. This all adds up to a quietly confident bike that is more stable than its 30lbs (with pedals and a tyre change) will belie.
The wheelbase comes out at 1200mm and with 432mm chainstays, its relatively stable without a monster truck feel. The short rear end help that snappy, punching out of corners feel whilst the slack head angle helps you point and shoot down the rough stuff with confidence. The flex stays provide a snappier more lively feeling, you get fired out of corner with precision and energy.
The suspension action is classic Stumpjumper, a little linear, meaning you might easily find the bottom of the travel on big hits, something that can be helped slightly by filling the shock with volume reducers to increase progression. Considering the geometry of this bike pushes you to take risks and go faster, the 130mm of travel will certainly be made the most of. Riding a short travel bike is like having the trail on loudspeaker in your ears, you aren’t cosseted at all like you are on a longer travel bike, you do feel the lumps and bumps in the trail and when things get wild a shorter travel bike will let you know, chattering over the rough somewhat. But nail brake points and speed and plough into this sort of terrain with certainty and it’ll see you through without a bink and with plenty of laughs.
With spec in mind, there are a few ways you can make your Stumpjumper better, should you purchase one. Get rid of the Butcher and Purgatory Grid 2.3" tyres. The Grid casing is the thinnest Specialized make and it's flimsy, you can reap the benefits of more grip and support by adding heavier carcass 2.6" Grid Trail tyres. Or like I have here, the excellent 2.5”WTB Verdict upfront, the weight penalty is diminished by the traction benefits you'll feel when descending
Given the short seat tube, the bike could also be adorned with a longer dropper post, I reckon I could fit a 170mm post in here but it won’t be the same for all riders so it looks like Specialized have erred on the safe side here in fitting a 150mm drop to the S3's. Everything else though is pretty neat, it's surprising how much better the Performance Elite 34 fork with its GRIP 2 damper is in comparison to the Rhythm fork found on the Comp models. It offers bags more support mid travel and is a worthy upgrade if you can afford this pricier bike.
I’d say if you like to feel connected to the trail, you like a bit of steep-tech and you like getting out on some cross country blasts then the Stumpjumper could be the all round bike you are looking for. It’s a neat, light, well designed bike that'll give its rider a hell of a good time downhill and then pedal back up without complaint.
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