It was no major shock to see Specialized unveil their first 650b bike this spring, and no doubt it’ll soon be just one of many. It does mean the Stumpjumper FSR EVO is now available in all three wheel sizes though.Why?Well, Spesh say customer demand was a key factor in bringing the 650b version to market.
The frame
Like the 26in Stumpy EVO, the 650b frame offers up
150mm (5.9in) of travel controlled by a custom,Autosag equipped Fox Float CTD
shock.On the Comp, this comes with Fox’s cheapest Evolution Series internals.
The BB is a Pressfit 30 number, there are ISCG-05 tabs for a chain guide and a
12x142mm axle boosts rear end stiffness.
We measured the head angle at 68.4 degrees – pretty
steep for a 150mm bike with 650b wheels. The chainstays are 15mm longer than on
the 26in bike but the wheelbase is still a relatively short 1,140mm.
The kit
The finishing kit is all from Specialized’s own
stable.Worth a mention are the Command Post BlackLite seatpost, which offers
three different saddle positions controlled via a bar mounted lever, and the
Butcher Control front tyre, which offers good grip and predictability even in
the wet.
The ride
The Stumpy EVO 650b is a fun bike to ride at trail
centres or on your local singletrack, where it gets on with the job at hand with
little fuss. It rides lighter than its 13.1kg (28.8lb) weight might have you
think, and you can thread it along tight, technical trails with relative ease
while maintaining decent speed. The geometry is reasonably well balanced too, putting
you in a good, fairly neutral position on the bike.
Although it has an ‘enduro friendly’150mm of travel,
you’ll soon find the limits of the Comp when you start to push things though.
Plough it into a rough, rooty section with harsh repetitive hits and, while the
back end continues to work away quite contentedly, the RockShox Revelation fork
starts to feel a little flexy and unsettled (the pricier Expert model uses the
stiffer Pike instead). The relatively steep
head angle makes it nice and nimble in the twisty stuff, but when you’re really
trucking you’ll wish things were a little more raked out up front.A shorter,
zero rise stem and lower-rise bar would help make things feel more confident up
front too.
On the climbs, our medium size sample provided just about enough cockpit
room to make clawing up even the steepest trails a comfortable affair, but you’ll
need to flick the CTD lever on the shock to help tame pedal bob from the back
end as you mash the pedals, especially at slower speeds. On the whole then, the
Stumpy EVO 650b is a fun bike to ride on technical trails. It doesn’t carry the
same speed as the 29in wheeled version though, and when things get more
‘grrr!’, there are more confident handling 150mm bikes out there.
FRAME M5 aluminium,150mm (5.9in) travel
FORKRockShox Revelation RC3,150mm (5.9in) travel
SHOCK Fox Float CTD Evolution w/Autosag
DRIVETRAIN SRAM S1250 cranks,X9 Type 2 rear mech,X7 front mech,X7 shifters
WHEELSET Roval 650b rims, Specialized HiLo Disc hubs, Specialized Butcher
Control (F) and Purgatory Control (R) 27.5x2.3in tyres
BRAKES Shimano Deore M615
BAR/STEM Specialized All Mountain, 750mm/Specialized XC,60mm
SEATPOST/SADDLE Specialized Command Post BlackLite/Specialized Henge
Comp
WEIGHT 13.1kg/28.9lb (w/o pedals)
