GT’s engineers have sure been busy.
They punted the previous Sensor
design and its 29-inch wheels in
favor of a totally new, low-slung 2014
Sensor trailbike line that will use 27.5-inch
wheels. In other words, forget everything
you know about the Sensor, because GT is
moving into a new era.
WHO IS IT MADE FOR?
The Sensors fall between the two
extremes of cross-country racer and downhill bike and blend the performance criteria of both. That means the Sensors are
designed to handle challenging singletrack
and downhills while still delivering enough
uphill performance to keep you in the saddle instead of hiking and pushing. Because
the Sensors appeal to the broadest number
of riders, GT offers five versions: three with
carbon frames and two with aluminum.
The $9220 Carbon Team leads the pack,
with our $7050 test bike coming in second.
The $4880 Carbon Expert, $3800 aluminum Expert and $2820 Elite follow.
WHAT IS IT MADE FROM?
The carbon fiber frame and stays form
what GT calls the “COR (Centered On
Rider) trail philosophy.” This is a catch-all
term that includes a frame design, which
moves the rider forward, a short handlebar
stem, wider handlebars, ID3 (Independent
Drivetrain, third generation), AOS (Angle
Optimized Suspension) and Pathlink, a linkage that is supposed to eliminate
the chain-growth sensation that plagues
many high-pivot suspension designs. The
big news is that the COR, ID3, AOS and
Pathlink technologies were developed
around 27.5-inch wheels.
WHICH COMPONENTS STAND OUT?
GT picks from an interesting mix of
suppliers to give the Sensor Carbon Pro a
very custom-built feel. You get e*Thirteen
wheels (don’t see that every day); a
Thomson stem; a Raceface three-ring crank,
bar and bottom bracket; Formula TI brakes;
and a RockShox Reverb Stealth seatpost.
Fox handles the suspension chores, and
Shimano covers the drivetrain, except for
the KMC chain and Raceface crank.
HOW DOES IT PERFORM?
The setup: GT went to great lengths to position as much weight as low as possible
on the chassis. That’s great for the bike’s
handling, but it makes rear suspension
setup a two-person job. The shock’s air
sleeve and CTD lever are the only visible
components, because the rest is tucked
inside the frame’s shock tunnel. There is
no way to eyeball the O-ring for setting sag.
GT gives you sag indicators on the frame
and Pathlink that are accurate, but you
have to have a friend read them for you.
On the trail: When a company messes with rider positioning, we get concerned. The 2014 Sensor rider is moved
forward relative to the 2013-model rider. This is not a
subtle tweak; it is a major shift. Thankfully, the new posi-
tion feels trail-rider upright and centered from the get-go.
We didn’t have to relearn to ride, and we didn’t experience
any muscle soreness after the first ride. If we jumped on
an old Sensor now, it would feel like our position was too
far rearward. The only ergonomic tic was that the wide,
elevated swingarm would occasionally make leg contact
Acceleration: Flip the shock to “Trail” mode, then stay
in the saddle and mash away. The Sensor and its 27.5-inch
wheels get up to speed in respectable fashion, and the drivetrain gives you plenty of gear options. Staying in the saddle
gives the rider a power position for accelerating (and climbing).
Cornering: The bike is precise and calm when hauling along
a curvy descent. The long wheelbase is noticeable in switchbacks and tight corners, but mostly because the rear wheel
will tag a rock or loose patch in the turn if you don’t compensate for it.
In the rough: Flat-edged hits catch the rear suspension
by surprise, and it hesitates moving through its travel if
riding in the shock’s Trail tune (set to the lightest setting).
Switch to “Descend” mode, however, and pedaling performance remains acceptable while helping, but not curing,
that mid-travel firmness. The chassis is plenty stiff enough
in these situations, so flex isn’t an issue. Still, the bike never
feels like you are riding on 5 inches of travel.
Climbing: The shock’s “Climb” mode is overkill. Leave
it in Trail mode, stay in the saddle and spin away. When
the climbs were rocky and loose, we left the shock in
Descend mode because it helped with small-bump compliance, kept the rear tire hooked up, and didn’t introduce
Descending: Drop the seatpost, open the shock (unfortunately a long reach) and have some fun. The fat tires,
27.5-inch wheels, low center of gravity and GT’s suspension
trickery all work together to create a fun downhill experience. The only bummer is that the chain banging on the hollow swingarm is loud. And speaking of loud, the e*Thirteen
freewheel is the second loudest in the business when coasting
(Chris King is still champ, but not by much).
Braking: The Formula T1 brakes deliver powerful and
consistent performance. The rear suspension firms under
braking to the point where you want to brake early to control
your speed and get off the binders in the corners. Our pads
squealed embarrassingly loud after water crossings, and they
took some time to quiet down.
TRICKS, UPGRADES OR TIPS?
First, you need to strategically apply a strip of Scotch 2228
moisture-sealing electrical tape to the underside of the drive-
side swingarm where the chain smacks it. Next, the Fizik
Tundra 2 saddle is brutally stiff for anyone short of a super-fit athlete. Replacing it with something like a WTB Rocket V
or Kore Durox Ti saddle will bring much-needed comfort.
We put a sizable ding in the e*Thirteen TRS+ rear rim
after hitting a square-edged bump hard. To the rim’s credit,
the damage did not allow air to escape the tubeless setup, and
we rode it for the rest of the test period.
The cable/hose routing is a work of art, and you better be
a gifted artist if you ever have to redo it. Our advice is to take
a bunch of photos clearly showing the proper routing before
you remove anything.
It is a good idea to fine-tune your rear suspension so you
can ride the bike in the Trail or Descend mode all the time.
We got great results working the shock’s CTD lever, but it is
such a long stretch to the lever (only 7 inches above the bottom bracket) that we feel is too dangerous to attempt if you
have already picked up speed on a descent.
Clearly, GT wants the Sensor to excel in the pedaling
department. The bike puts the rider in a power position
with 27.5-inch wheels, an ultra-versatile drivetrain and
laterally stiff everything. If you have been riding a trailbike that forces you to hike-a-bike the hills because of its
weight or pedaling performance, the Sensor Carbon Pro will get you to the top without forcing you to take the
bailout line on the way back down.