PINKBIKE FIELD TEST
GT SENSOR CARBON EXPERT
GT's redesigned Sensor pays homage to the famous LTS.
Words by R. Cunningham, photography by Trevor Lyden
LTS stands for Linkage Tuned Suspension (who knew?) and it was also the name of the dual-suspension trail bike that put GT in the game back in the day. The 2019 Sensor marks their return to a conventional four-bar, linkage-driven rear suspension, and a concerted effort to rekindle the one-bike-to-ride-everything spirit that turned mountain biking into a social revolution during GT's golden years.
The 130-millimeter-travel Sensor Carbon Expert carries a $3899 USD sticker price and shares the same half carbon, half aluminum frame as the $5000 Sensor Carbon Pro and its more affordable sister, the Sensor Carbon Elite.
GT Sensor Carbon Expert Details
• Travel: 130mm rear /front
• Wheel size: 29"
• Frame construction: carbon / aluminum
• Head angle: 65.5º / 65.98º
• Seat angle: 76º / 76º.48º
• Sizes: SM, M, L, XL
• Weight: 29.5 lb (13.4 kg) size M, w/o pedals
• Price: $4200 USD
• More info: GT Bicycles
Give the Sensor Carbon Expert a walk-around and it's apparent that you are getting a hell of a lot of bike for under four grand. Start with 29-inch wheels and add a 12-speed Eagle XO1/GX drivetrain, a 130-millimeter RockShox Revelation RC fork, paired with a Deluxe RT3 damper. The handlebars are wide and the cockpit is steep in the back and slack up front - which is a good thing. GT's shock-mount flip chip can be used to toggle between a 65.5 and a 66-degree head-tube angle, with a corresponding shift at the seat tube angle. We left ours in the low, slack position, 'cause that's how we like our trail bikes..Climbing
Judging from the Sensor Expert's build, 29-inch wheels and modern numbers, I expected it to roll smoothly over the area's ceaseless roots and be calm at the controls. Instead, GT's take on the trail bike pedals and rides almost as firmly as I'd expect from an XC racer. A steep seat tube angle and zealous support from the rear suspension eliminated any settling while climbing. With or without employing the shock's low-speed compression lever, I could hammer on the pedals willy nilly and the GT would convert my effort into forward motion.
That didn't necessarily make the Sensor a great climber. Its rear end felt notchy while powering over roots, especially at slower speeds. There are many zones where high anti-squat values and mega-firm pedaling are hallowed trail bike attributes. None of those places, however, are located in the Pacific Northwest. The GT would ease into a fast tempo on the smoother sections of a climb only to bog down three meters up the next root garden. Experimenting with shock settings (like Cannondale, GT recommends a maximum of 25% sag at the shock) did little to soften the rear suspension. Low tire pressures (21 psi front and 24 rear) helped, but speed was really my only savior. Like a hardtail, the Sensor hydroplaned over the chunder as long as I stayed on the gas.
Negatives aside, the Sensor was rarely lacking for grip. Overcome your frustrations, keep the power on, and the GT could top technical sections that would raise the eyebrows of experienced observers. No doubt, some of that traction was generated by its shopping-bag-thin, tan-wall Schwalbe Nobby Nic tires which wrapped around nuances in the trail in a way that only an invertebrate life form could duplicate. More on that later. Descending
Both riders who field-tested the Sensor Carbon commented that we were being pushed forward on the downs. The solution was to up the fork's air pressure and add a touch more low-speed compression. The culprit was that the rear suspension was riding high and overdriving the fork. Normally, the solution would be to soften the shock, but it seemed were were fighting rear suspension kinematics, not damping or spring pressure in this case. The resulting ride was still firm, but much better balanced, and the GT responded by becoming a composed descender.
SRAM's Level brakes lacked the sophistication you'll need to finesse the Sensor downhill at speed, but stay at 80% and the GT will have you dropping down boulders, or drifting loamy corners until you run out of altitude to burn. Steering is light, but not wiggly, and the fork's 51-millimeter offset works well with the steering geometry for those times when you need quick steering inputs to thread down a tricky chute. Rough surfaces at speed, will have the Sensor drifting both wheels with minimal drama until the suspension is no longer overwhelmed and the tires find consistent grip again.
GT needs to upgrade the Sensor before it's going to reach its full potential. The tan-wall Schwalbe Nobby Nic tires were a laugh. They should be renamed "El Chapo" because the air usually escaped before we had put the pump away. You didn't have to ask if I was riding the GT - the Stan's sealant on my kit was the giveaway. Another miss was the 120-millimeter-stroke seatpost on the medium-sized bike. It should have been a 150. I am only five-foot, seven inches and there was plenty of extra post showing above the clamp. Cash can fix those gaffes, but GT will need to tame the Sensor's ill-tempered rear suspension before its 130-millimeters of wheel travel will feel adequate for the aggressive trail bike category.
Note: The shock tune on the Sensor has been changed since we conducted the Field Test. Our test bike had a medium rebound, medium compression tune and two volume tokens, which has been switched to a low rebound, low compression tune and three volume tokens. This should help improve some of the small bump sensitivity issues we were running into.
In addition, bikes are now shipping with an extra inch of steer tube, allowing riders more room to find the ride height they prefer.