Short Term Shakedown of the... Specialized Stumpjumper FSR Comp Carbon 6Fattie 27.5+ Mountain Bike 2016

Ok, I like my bike - a Specialized Camber Comp 29er 2016 - so was disappointed to find out that the front shock was in fact only giving me 100mm of the 120 it promised.  The result, was sending the shock back to Rockshox to be fixed under warranty, or fixed at my own cost.  Either way, it would mean being without my full suss for a period of time, and I really didn't want to head back to my hardtail to get my riding kicks.  Luckily, I have a friendly bike shop who said they could sort out a 'loan bike' for the time the shock was being fixed (or until somebody else wanted to try the load bike).

So I arrived at Cycleworks, handed over my bike (or rather the faulty shock), and was handed an elegant looking Specialized Stumpjumper 650b Fattie.   It felt lighter than my bike, and the wheels were noticeably wider... though I think they are not as wide as the 'fat bike' standard.  Hence it is called '27.5+'.  I have wanted to try a 27.5 for a while, as it is what everyone goes on about, so this would be a step closer to it from my 29er.  Also, I was interested to try a 'carbon' framed bike out, as again, it's what folk go on about.  Basically, this was in theory a better bike than mine.

Shakedown in The Punchbowl

I took it out for a ride as soon as I could.  The setup was very similar to mine, though the dropper post was pretty violent when pressed, making me think that mine is low on pressure.  Another point, is that when the dropper goes down, it seems to move forward, making it easier to get low behind the saddle.  I would guess the seat post angle is bigger, to allow this to happen.  The handlebars seem wider, but I couldn't be certain.
First impression when peddling, is that it accelerates fast, and with ease.  The big tyres didn't feel cumbersome, and didn't give much road noise (I was running them at 20psi, though was told I could go lower).

After the road section of my ride, I head onto loose sandy / rocky track, and the bike had no problem. It actually felt like it floated over the chunky parts, and without much effort.  Bearing in mind I was used to less travel shocks, it would be expected, but I'd say it was fun and quick to climb.  On off camber sections, it held it's edge, but it was too early to draw any conclusions.

A I approached my first downhill, I dropped the post, and noticed the seat coming forward, and accelerated - the gears were pretty slick (pretty sure they were SRAM, meaning my current ones are Shimano).  It had no problem with the roots - and the ride was very even and quick, and I felt it kept the line I was taking.  I basically felt more connected with the ground, and it was really fun

Then on to the climb, which was steady - I'd say an improvement on the Camber.  This is odd, as most would say the 29er is perfect for the climbs.. though I'm not really comparing like for like, as the carbon frame may make a difference.

The ride then progressed, and I got to know the bike, and again, it was fun.  The acceleration was definitely plus - it just shoots away.  When I arrived at my favourite local downhill section (Patricks Passage), I was looking forward to what it could do.  I know this trail very well, but am always a little cautious on the top, after a few tumbles there.  Still, it ate up the roots, and rolled quick over the rocks.  I still felt the bumps, but in all fairness, I hadn't checked any of the suspension settings, so was just assuming the rebound was set as standard, front and back.  The usual jump, halfway down, was soaked up, though I was travelling so fast, as it was getting pretty boggy.

By the bottom section, I was wishing I'd transferred some front mudguards over, as I was getting totally splattered.  I kept the speed up into some deep mud, and the bike lost it's grip.  I'd go out on a limb and say that this would not have happened with the Camber... but I'd need to ride the Stumpy more to get a definitive opinion.  For now, it doesn't seem to handle so well, at speed in deep mud... I guess the big tyres act more like dinghies.

Later, in the thick sand section of my ride, the bike shone again.  It was wet sand, but still it seemed to hold it's line well.

In all it was a really fun bike to ride.  Next stop Swinley - lets see how it handles a purpose made bike trail - I may even lower the tyre pressures!

The Fattie at Swinley

Swinley is very different to my local riding conditions.  The tracks are purpose built, there are huge berms, jumps etc, and all in a 13 mile circuit (half blue, then red, then second half blue).  As before, the bike felt good under acceleration, and was good cornering.  However, when I pushed it, on the super fast Red 15, I wiped out.  Wheels basically lost grip with the trail on the corner, and with no bank to push against, it was kind of bound to happen.  I may possibly not have attempted the turn at such speed on the 29er, but still, it re-enforced my view that it could be skittish around the front end when cornering.  Luckily I was wearing my knee pads, so no harm done, to me or the bike, but it was interesting to experience.  I had checked the tyre pressure before I went, and had it at about 18psi.  Could I actually take it lower, and expect more grip?  I let a little air, and slowed the rebound of the front fork slightly.  There is so much experimentation with these setups, but it's worth doing.  My feeling is that I could take the tyres right down in pressure.

I did notice the lower bottom bracket - in the way that my pedal strokes caught on the trail where they wouldn't usually.  This led to a frustrating 'foot down' in The Labyrinth...  In the same section, I was aware of the width of the bars, though I'm not 100% sure they are actually any bigger than the Camber.

As a whole, my times around Swinley weren't any quicker (a few were), but I'd have to put that down mostly to me being in the depths of man-flu... I wasn't quick up the hills, and didn't have energy down them.  I'd have to head back again when I'm on form to get a more accurate feel for the bike.  That said, it was great over the nobbly trails, and easy to twist and turn in the long berm filled blue section.  And it flew over the roots as before.

I noticed a creak, presumably from the headset - I would guess from the bottom bearing... as I had the same on the Camber.  Can't they design anything to stop this form happening, or is it a design flaw?

Once again, I noticed the front end felt noticeably lighter and livelier - though this could be too much rebound on the front shock, or too higher tyre pressure.  I actually think it's because it's a lighter bike.

The Technical Details (taken from tredz.co.uk)

"Specialized Stumpjumper FSR Comp Carbon 6Fattie 27.5+ Mountain Bike 2016
Product description
The new 2016 Stumpjumper FSR Comp Carbon 6Fattie is a fun, full sus MTB that is ready to take on anything. With the new 27.5 plus (650+) wheel size the 6Fattie Stumpy is a mountain bike that is at home on the most technically demanding trails.
You get the same diameter 650b wheels with wider 3” tyres that are accommodated with a plus sized fork and a wider 148mm Boost rear hub.
These 3” tyres give you more grip and extra float. The additional grip allows you to corner faster, brake later and nail those technical climbs. The extra float supplements the suspension so it feels like you have more the 135mm (150mm front) of travel.
Rolling resistance increases slightly but this is far less important than the extra grip you get in return.
At the heart of the FSR Comp Carbon frame is a FACT 9m front triangle with a M5 alloy rear. The FACT composite front is super stiff, light and strong. The SWAT door offers storage in the down tube for trail essentials meaning that you need to carry less weight in your backpack.
With a slack head angle, short chainstays and low bottom bracket height the Stumpjumper 6Fattie shares the same dialled angles as the regular models. This translates into stability at speed and a lower centre of gravity for better handling in the corners.
The Fox 34 Plus Performance fork offers premium level trail performance with 150mm travel that matches perfectly to the DPS shock that controls the fully active FSR rear suspension.
RX trail tune on the rear suss means that every shock has the volume, compression and rebound range tuned for each Stumpy. You don’t get this from every manufacturer.
The new SRAM GX 1x11 drivetrain offers all the gears that you need in a simple system that offers excellent chain retention. Specialized Deore hydraulic disc brakes are powerful with great modulation. Control your speed with confidence.
Hit the trails with more traction and control with the Stumpjumper FSR Comp Carbon 6 Fattie.
Key Features:
27.5+ tyres offer more grip and float
FACT carbon composite frame is lightweight and stiff
Fox Float shock and 34 fork for plush suspension travel
SRAM 1x11 speed drivetrain offers a wide range of gear ratios
Sizes: Small, Medium, Large, X Large
Colour: White
The Stumpjumper FSR Comp Carbon 6Fattie is available with 0% APR finance

The Specialized Stumpjumper FSR Comp Carbon 6Fattie 27.5+ 2016 Features are:

Frame: FACT 9m carbon, Trail 6Fattie Geometry, FACT IS carbon construction, M5 alloy rear triangle, SWAT Door integration, PF30 BB, fully enclosed internal cable routing, 135mm travel 

Rear Shock: FOX FLOAT Performance DPS, AUTOSAG, Rx Trail Tune, Kashima coating, 197x47.6mm 

Fork: FOX 34 Plus Performance, 150mm travel, 3-position compression adjust, tapered steerer, 51mm offset, 15mm thru-axle 

Headset: Hella Flush, 1-1/8" and 1-1/2" threadless, Campy style upper w/ 1-1/2" lower, cartridge bearings 

Stem: Specialized XC, 3D forged alloy, 4-bolt, 6-degree rise 

Speed: 11 

Rear Mech: SRAM GX X Horizon, 11-speed, alloy cage 

Chainset: Custom SRAM GX-1000, carbon, PF30 spindle, 28T, direct mount

Bottom Bracket: SRAM, PF30, OS press-in bearings, sealed cartridge

Cassette: SRAM XG-1150, 11-speed, 10-42t

Chain: KMC X11L, 11-speed, w/ reusable MissingLink

Front Brake: Shimano Deore, hydraulic disc, Ice-Tech resin pads w/ fins 

Rear Brake: Shimano Deore, hydraulic disc, Ice-Tech resin pads w/ fins 

Rims: Roval Traverse 650b, alloy, disc, 29mm wide, 24/28h 

Front Hub: Specialized, Hi Lo disc, sealed cartridge bearings, 15x110mm thru-axle, 24h 

Rear Hub: Specialized, Hi Lo disc, 4x sealed cartridge bearings, 12x148mm thru-axle, 28h 

Tyres: Specialized 6Fattie Purgatory Control, 60TPI, 2Bliss Ready, folding bead, 650bx3.0" Front Specialized 6Fattie Ground Control, 60TPI, 2Bliss Ready, folding bead, 650bx3.0" Rear

Seatpost: Command Post IRcc, cruiser control technology, micro-adjust height adjustable, alien head design, bottom mount cable routing, remote adjust SRL lever, 30.9mm, S: 100mm travel, M/L/XL: 125mm 

Pedals: Nylon, CEN std., w/ toe clips"

Checkout a video comparison made by GMBN - 27.5 versus 27.5+: