The stumpier Stumpjumper shows that plus doesn’t have to mean fuss

All-alloy version of the plus-sized Stumpy

If Specialized’s regular Stumpjumper isn’t Stumpy enough for you then – as you may have heard if you’re a regular reader of these pages – there’s now a range of plus-sized models.


Known as the 6Fatties, each of these bikes roll on tires that are 3in wide. The difference with this Comp model however, and we are speaking relatively here, is that it doesn’t cost an absolute fortune. Actually it retails for $3,499 and that makes it a full $1,000 cheaper than the next plus-sized Stumpy in the range – and a full US$5,100 cheaper than the wallet-violating S-Works model that we’ve recently rated very highly.

Related: Specialized Stumpjumper FSR Comp Carbon 6Fattie

Still, that’s a $600 premium over the 650b or 29in Stumpjumper Comp models, which both use 2.3in tires .

In order to hit this price point, Specialized has switched over to an all-aluminum frame for this model – though its smoothed welds and complex tube shapes do their best to tell you otherwise.

Smooth welds and creative tubes will have a lot of people thinking this is a carbon bike:
Smooth welds and creative tubes will have a lot of people thinking this is a carbon bike

Rather than stump (sorry) for the 150mm of suspension travel offered by the regular 650b Stumpy, this model delivers 135mm of travel at the back wheel – the same as the 29in Stumpjumper. Unlike the 29in Stumpy however, the Comp 6Fattie gets a 150mm fork – the same as the 650b Stumpy.

Familiar geometry

Geometry-wise the plus bike is actually very similar to the regular 650b Stumpy, matching its same 74-degree and 67-degree seat and head angles. The 437mm chainstay length of the plus bike is the same measurement as that of the 29in Stumpy, but the fatty places its bottom bracket lower than both the regular-tired bikes at 331mm.

Related: Marin’s back to basics plus bike is one to watch

Another factor that’ll have a big influence on the bike’s handling is the fork offset, which at 51mm is longer than that of the 29in bike. Let’s talk more about the fork for a moment: its a 34-series model from Fox, a fork that’s been completely redesigned for 2016. This is the Performance version, which goes without the fancy FIT 4 damper; instead it gets a three position compression adjuster at the top of the fork leg. The performance of this particular fork remains a mystery to us at the time of writing.

The roval rims are curiously narrow with an internal diameter of just 29mm:
The Roval rims are curiously narrow with an internal diameter of just 29mm

Suspension at the rear is handled by a Fox Float DPS shock complete with the company’s RX trail tune. The original equipment shock also gets Specialized’s proven Autosag system, which consists of a smart valve that allows any rider to quickly and consistently find their recommended sag level. Like the front damper, the Float shock also belongs to Fox’s cheaper Performance series meaning, just like at the fork, you get a three-position compression adjuster with open, medium and firm compression settings.

Big talking point

Of course, the tires on this bike are a whole talking point in themselves. They’re 3in versions of Specialized’s Purgatory (F) and Ground Control(R) tyres and both are tubeless ready. The tires are paired to Roval Traverse 650b rims, with an inner width of 29mm – the same as those fitted to the regular 650b bike.

It’s a different approach to say, Scott. The Swiss brand is choosing to run rims with an internal width of around 40mm for its plus-sized bikes, which actually run on narrower 2.8in tires.

Plenty of room back here, despite the 3.0in rubber:

Plenty of room back here, despite the 3in rubber

Specialized has also equipped a 1×11 version of SRAM’s GX drivetrain. You’ll still find another lever on the left side of the handlebar though – that’ll be to control Specialized’s own Command dropper post, which offers 100mm of travel in all sizes apart from small frame bikes (those will get a 75mm version). Finishing kit is mostly supplied by Specialized and includes a short own-brand stem and 750mm low-rise handlebar. Slowing down is a job handled by Shimano Deore hydraulic discs, which arrive with Ice-Tech finned pads as standard.


This size XL test bike tipped our scales at 14.2kg/31.3lbs without pedals. As usual, stay tuned for a full review.