Cube have kept their strong 29er race hardtail range for 2014 but added four new bikes with 650b wheels. The Reaction GTC Pro 27.5 is the second-tier carbon model.
The frame
The frame is built from Cube’s Pro Composite Series carbon. The short
tapered head tube lifts up into a big down tube that expands and flattens into
a rectangular section at the pressfit BB. The deep triangular chainstays kick
up at the end so the brake can be mounted on the chainstay and the carbon QR
dropouts use a replaceable threaded gear hanger for crash proofing. Cables are
routed through the down tube, with the rear brake hose run externally for easy
servicing. There’s plenty of mud room at the rear and a side-slotted seat tube.
The kit
The Reaction feels practical thanks to its 720mm bar and 80mm stem.
There’s no missing the big lockout lever for the 100mm (3.9in) travel Manitou Marvel
TS Air fork. For 2070$ we’ve no complaints about getting Shimano SLX and XT kit
on a carbon frame, and the ownbrand finishing kit is good gear.
The ride
The decals make it clear that this is a bike focused on speed, and while
overall weight isn’t particularly impressive, the low-treaded tyres and
mid-size wheels mean it’s noticeably keen to get moving. The fat front end and
deep chainstays let you put plenty of grunt into the back wheel through the grips
and pedals.
The sculpted rear stays and flex from the long 27.2mm seatpost help
smooth out chatter when skimming over rocks and roots. While some cost-conscious
carbon bikes can feel brittle, skittish or dull, Cube’s lay-up gives the bike a
well balanced, positive but not punishing character. It’s a frame with a clear
stiff front/springy rear bias.
The 70-degree head angle puts the front wheel where you need it and the
short back end lets you whip the rear out at speed. The Reaction GTC Pro wheelies
and drops off rocks OK and is an enjoyable frame to ride, not just a
single-mindedly fast one. Several of the component elements compromise rather
than complement the ride though.
Most obvious is the Manitou fork. While the mid stroke is reasonably
smooth, the start is notchy and we had a regular undamped top-out clank that got
worse after a small oil leak began after two rides. The skinny stance and QR
axle mean noticeable twang and twist once you start pushing hard through
corners or hauling on the anchors too. This makes the already slippery
hardcompound tyres even harder to control if the trails get damp.
From experience, the flexy-feeling SUNringle Radium wheels don’t last
that long in the wet without regular TLC either. Between them, the wheels and
fork negate most of the sharper, stiffer, more dynamic edge that 650b wheels potentially
give over 29in in race or ‘fun trail’ terms.
FRAME GTC carbon
FORK Manitou Marvel TS Air, 100mm (3.9in) travel
DRIVETRAIN Shimano SLX cranks and shifters, Deore XT mechs
WHEELS SUNringle Radium MA wheels, Schwalbe Rapid Rob Active Line 27.5x2.25in
tyres
BRAKES Shimano Deore M615, 180/160mm
BAR/STEM Cube Race Flat Bar Pro, 720mm/Cube Performance, 80mm
SEATPOST/SADDLE Cube Performance/Selle Italia X1
WEIGHT 11.6kg (25.6lb)
PRICE 2070$ (complete bike)
