TESTED: The Specialized Stumpjumper FSR S-Works 6Fattie
Unless you’ve been living under a rock for the last couple of years you’ll definitely have noticed that wheels and tyres in the mountain bike industry have been getting bigger.
Unless you’ve been living under a rock for the last couple of years you’ll definitely have noticed that wheels and tyres in the mountain bike industry have been getting bigger. The fatbike started it all, giving riders a taste of what was possible on the trail when you had to worry less about the ‘right’ line and the camber and could just focus on the most important thing – fun. But not everyone (well actually almost no one) wants a fifteen kilo trail bike these days and so the combined industry created the Plus genre. A stunning hybrid between our regular trail bikes, but with the added traction and control benefits of running around a three-inch tyre. Specialized were one of the first to get properly involved in the manufacture of Plus bikes, with multiple models in their existing range now sporting a Plus sized twin. The S-Works Stumpjumper FSR 6Fattie is their top of the rung Plus offering.
Initial Impressions of the 6Fattie
If you have a glance at my current personal posse of bikes you’ll notice I don’t currently own a bike with tyres under three inches, I’m definitely Plus converted and I was excited to see how the 6Fattie compared. The main triangle is constructed from Specialized’s FACT carbon fibre which keeps the weight down and stiffness up and has some interesting features we’ll discuss in a minute. The 6Fattie retails for just over five figures and it was with this in mind that I was a little surprised to find that it features an aluminium swing arm.
The first thing that strikes you about any Plus bike is the chunkiness of the tyres, and with the 6Fattie’s understated gloss black and yellow colour scheme, slender frame and the deep section Roval rims this is definitely accentuated. It’s the kind of bike you show up to the trail on and other rider’s jaws hit the floor.
It’s equally a drool fest in the specification department with little on the 6Fattie that could possibly be upgraded. The full SRAM XX1 drivetrain with a Boost twenty eight tooth chain ring is paired with Shimano’s XTR Trail brakes rocking a 203mm rotor up front and a 180 out the back. A Fox Racing Shox Factory 34 fork offers 150mm of travel up front matching up nicely with the Factory DPS rear shock also from Fox. The shock also features Specialized custom RX Trail Tune and patented Autosag making initial setup a breeze.
The whole package rolls on the Roval Traverse SL 650b SL wheel set and Specialized’s Purgatory Control and Ground Control tyres in 3.0”. The Traverse SL is actually the exact same wheel set that Specialized spec on their standard 650b Stumpjumper. and at ‘only’ 30mm wide I was initially curious about what kind of pressures I was going to be able to get down to during the test. I’m not a heavy guy, nor am I a trasher of wheels but the low spoke count (twenty four spokes front and twenty eight rear) on the Traverse SL caused my eyebrows to raise slightly given my usual personal preference for thirty two spoke, three-cross wheel sets. Based on appearance alone the Specialized tyres looked like they’d be fun with plenty of small, fast rolling knobs and a big footprint. A Syntace stem puts the Specialized FACT carbon bar in the right spot for you to steer and a Specialized Command Post IRcc allows you to sit and pedal, or gets out of the way when things get a bit rough and tumble.
One of the most interesting features of the 6Fattie is the use of Specialized’s SWAT technology. An Acronym of Storage, Water, Air and Tools, the SWAT concept basically revolves around creating innovative ways to store and access stuff you need while riding. The 6Fattie frame feature SWAT Door Integration. Basically there is a sneaky trap door underneath the bottle cage on the main triangle that features a padded tool roll for rattle-free storage of a spare tube, pump and other necessities. Unfortunately it is too small for a can of beer. There’s also the SWAT multitool near the shock mount and the chain tool that is intergraded into the top cap inside the fork steerer. A chain tool is one of those tools you’ll rarely need but when you really do, you REALLY do and the SWAT system ensures that you’ll never accidentally leave it at home. Pairing up the on-bike SWAT with Specialized’s SWAT bib short you could probably go for a two hour ride in an Australian summer and not take a Camelbak. That’s pretty nice.
On The Trail with the 6Fattie
As expected, suspension set up on the 6Fattie was super simple thanks to the Autosag feature on the rear shock. Pump the shock to 300psi, sit on your bike, release the Autosag valve and the shock automatically releases air until ideal ride-height is achieved. Easy.
The first thing that grabs you about the 6Fattie is how quickly it rolls despite the girth of rubber underneath you and performance on smoother, open trails was akin to a ‘regular’ 650b bike. I think a lot of riders may tend to look at Plus bikes and make an assumption regarding their ride weight and feel and to be fair they do LOOK like they’d be more of a handful to manoeuvre. This is not the case with the 6Fattie and even as an experienced Plus bike rider I was impressed by the light, crisp feel of the bike. The low wheel weight and stiffness of the main triangle definitely play a big part here and the 6Fattie accelerates and turns with a nimbleness that will definitely put a smile on your face.
If you are coming from riding bikes with standard two-point-something tyres the amount of traction on offer from the Specialized three inch rubber will no doubt amaze you as the cornering, braking and especially climbing traction relative to a traditional setup is huge. That said, my personal Plus bikes are set up with rims between 40 and 50mm wide and on a big wide rim like that pressures as low as 14psi are achievable for aggressive trail riding. It’s at these kind of tyre pressures that the Plus genre will absolutely blow your mind as all kinds of previously off limits lines become available to you and the way you look at the trail is permanently changed. As mentioned above, the 6Fattie runs the same 30mm wide wheel set as Specialized’s Stumjumper FSR 650b which comes set up with 2.3 inch tyres.
With the 30mm rims I could comfortably get the tyre pressure down to 19psi, not much lower than a regular 650b tyre, but any lower than that and the tyre would start to feel a little squirmy when cornering and fear of rolling a tyre off the rim had me reaching for the pump.
Regardless, even at 18psi the tyre footprint in huge, there is an abundance of grip and you’ll find yourself looking for looser and rougher lines. If you’re the kind of rider that struggles with climbing traction, or descending confidence, the 6Fattie is certain to remedy a large amount of that for you. Coming screaming into corners faster than you probably should is quite achievable and the Purgatory front tyre makes a good team mate for the big XTR rotor up front and will pull you up on a dime even in the loosest conditions. Under this kind of very hard braking there’s definitely a noticeable amount of flex in the front Roval wheel as the twenty-four spokes (which are radially laced on the non disc side) really struggle to deal with the force. This was not so bad as to be off-putting, but may be more of an issue for heavier riders.
As mentioned, the main aim of the Plus genre is to allow the rider to focus less on trail surface conditions and simply get more fun out of their daily ride. During a group ride mid test a few friends threw a leg over the 6Fattie and the feedback was all the same. ‘It’s like you can take whatever line you want!’ If the 6Fattie was your main ride, and you started to really get a proper eye for what it was capable of on the trail, it would be pretty hard to go back to riding ‘skinny’ tyred bikes again.
Our Take
This is a really fun bike. The previously non existent mix of low weight, huge traction and simplicity of setup make the S-Works Stumpjumper FSR 6Fattie an amazing choice for the committed, but not overly aggressive rider looking for a top shelf, laugh out loud fun trail machine that’s light and efficient enough for all day exploring but can hold it’s own when things get loose and gnarly. Those looking for something a little more affordable would get a similar, if marginally heavier, experience from the Comp, Comp Carbon or Expert models of the 6Fattie which start at around $3990
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Tester: Adam Macbeth
Riding Experience: Has done many skids over many years
Generally Rides: Devinci Hendrix, Norco Torrent, Salsa Blackborow,
Height: 179cm
Weight: 74kg
Bike Test Track: Secret Trails
Three things you liked about the bike:
1. Loads of traction
2. Nimble, predictable handling
3. Changes the way you look at the trail, for the better
Three things you would change about the bike:
1. Wider rims to access properly low pressures
2. Swing arm should probably be carbon at this price.
3. Stiffer wheels
RRP $10999 (as tested)
Weight 13.4kg (as tested)
