GT's timing could not have been better, with the Atherton's double-double downhill victory coinciding with its 2014 product launch in Park City, Utah this weekend. The festivities took place at the Chateaux resort, where we were shown GT's full lineup of its all new Fury DH bike at four price points - and two very promising 650B trailbikes. The vibe was that GT has re-committed to producing a range of bicycles that are worthy of the brand's heritage - when the marquis was a proud symbol of all things good in our sport. If GT demonstrates that it has the staying power to carry this effort through the present decade, the heavy hitters that are leading the market today will have to give up a top spot on the hot seat.
Two New Trailbikes
Two years after the first prototypes were being tested in Germany, GT released its 130-millimeter-travel Sensor and 150-millimeter-travel Force at Park City. Both are built around 650B wheels and there are no plans to offer a 26-inch model in either the trail or all-mountain categories now, or in the future. The Force and Sensor are framed around two different chassis designs that, while they may share some common parts, are designed with different geometry, and cut distinctly different profiles.
Dan Atherton leads Hans Rey on a test session during the development of GT's 2014 Force and Sensor. Both athletes were essential throughout the process, with Atherton pulling hard for the 150-millimeter-travel all-mountain Force and Rey giving the major input for the trail-oriented Sensor. Hans has a signature Sensor model in GT's lineup.
The top offerings all feature high-modulous carbon construction, but GT also produced affordable aluminum versions to ensure that most of its core customers could pony up for a new Sensor or Force should the spirit move them. At the heart of the new bikes is a high-pivot rear suspension which is controlled by a simplified version of GT's Independent Drive four-bar linkage called 'Angle Optimized Suspension' (AOS). GT backs up its new chassis with trail worthy components too. The short version is; great pedaling, low bottom bracket heights, slack head angles, extended top tube lengths and much lighter overall weights than anything GT has fielded in the history of its dual-suspension trailbike lineage.
Dan Atherton, the spear point of GT's Enduro team, swore off 650B wheels at first, but after helping to dial in the geometry and ride of the new 150-millimeter-travel Force, he changed his mind. Atherton says, however, that he will continue to develop the 26-inch wheel prototype enduro GT he uses on the racing circuit.
The new Force is designated as an all-mountain bike that is more trail-oriented. GT was secretly testing and developing its 650B Force in Germany, where its design team, headed by Peter Denk, began with a list of performance demands and a blank computer screen. A number of aluminum test frames were built with adjustable suspension locations and in differing frame geometries to zero in on the right mixture of bomb-proof descending and XC-worthy climbing. Real-time testing by the likes of Dan Atherton and Hans Rey was backed up by electronic data acquisition in Germany and when the prototype Force was ready in principle, the final frame design was handed over to GT's Jeremy Mikesell, who took the suspension hardpoints and frame numbers and crafted them into a sleek, high-modulous carbon frame. The result was a medium-travel ripper that feels low and slack - but won't disappoint in the climbing and acceleration department.
GT's 2014 Force Carbon Team. Complete geometry and final prices were not forthcoming at GT camp, but the most important numbers for the medium frame size are: head angle - 67.2 degrees, seat angle - NA, top tube length - 59.9 mm (23.6 inches), bottom bracket height - 347.9 mm (13.7 inches) and a wheelbase of 1162 mm (45.75 inches). The Force Carbon Team frame is reported to weigh 2.89 kg (6.36 pounds with shock) and the bike is said to weigh under 30 pounds.
New Suspension Platform
Force frames feature an exaggerated high-pivot swingarm (technically, the frame's seat stays) that is large enough in all dimensions to resist the torsional stress meted out by a pro downhiller. GT's Independent Drive system was redesigned and simplified and is now called 'AOS' for Angle Optimized Suspension. The effect is exactly the same, however, with the bottom bracket swinging slightly back and forth to track the swingarm's rearward arc'ing axle path to eliminate all but a smidgen of its unwanted chain-growth effects. More about that later, all you need to know now is that AOS keeps the suspension moving without adversely affecting pedaling action and that the high-pivot swingarm gives the suspension superior performance over ragged terrain.
Closeup views of the Force Carbon's triangulated head tube (top left). The AOS version of GT's Independent Drive system is built around a hollow aluminum rocker called the 'PathLink' which houses the bottom bracket. And and a look at the clevis-pivot at the rear dropout. The Force and Sensor share AOS suspension and also use direct-mount rear derailleurs.
The Force frame is built with lateral stiffness in mind, but it is one of the lighter dual-suspension frames that GT has produced. Large-diameter frame tubes and wide, 15-millimeter suspension-pivot axles keep the frame stiff and light. Cables run externally below the down tube and the dropper seatposts are internally routed through a port behind the seat tube. To keep the bike's weight low, the Fox CTD shock is driven by the upper end of the PathLink and through a seat tube tunnel. The 12-millimeter through axle uses a Maxle release system and all of the major frame pivots are clamped in place. The new frame design looks much cleaner and simpler than anything that has come from GT in a while - and the aluminum version is an identical copy. Sizes offered are X-small, small, medium and large.
GT offers the Force Carbon frame at two more affordable price points: the Pro (top) and Expert may lack some bling, but we'll bet the performance doesn't suffer all that much.
GT got the parts right on the Force, with a Shimano XTR transmission, Fox's latest Kashima CTD suspension, headlined by a Float 34 fork, tubeless Continental Trail King tires, wheels from e-thirteen, a RockShox Reverb Stealth dropper post, and a 760-millimeter handlebar sitting on a 60-millimeter stem. The only questionable choice was the Shimano triple crankset, which GT's mountain bike marketing director defended as a choice that they made to cater to the booming European market. I must not have drank the same Koolaid. Dan Atherton's Force used a single, 32-tooth chainring and he was going pretty fast. I am sure that GT did their homework, but I would be happier with a 34/22, two-by crankset. The good news is that you can ditch the 40-tooth sprocket and switch it out with a bash ring.
Pinkbike's First Impressions
The new Force is everything we wanted its older brother to be: lighter, lower, slacker, better uphill and smoother on the downs. The component spec is almost perfect and the Force is targeted at the center of the mid-travel AM/trail market. The choice to go with the mid-size wheel format plays well with the wide-spread acceptance of 650B on the opposite side of the Atlantic Ocean, and for the building sport of Enduro Racing. It is good to see GT swinging for the fence again and the new Force should be a home run. We'll let you know when we get one home and complete a full blown review.
Hans Rey is a huge fan of the 130-millimeter-travel Sensor, and GT used his input to craft its performance to suit top bike-handlers who want a lighter, snappier handling trailbike, compared with a typical all-mountain bike. One that will respond to leg power in the style of a dedicated XC machine.
The new Sensor is targeted at XC/trail riders who want a fast-paced climber, but who demand good manners from the bike when descending, or when attacking technical trails. The blueprint for such a bike is well understood - what GT's sensor promises to bring to the game is its high-pivot AOS suspension. The same system as the Force uses, AOS adds more big-hit response to the Sensor's 650B wheels. It had better, because at 130-millimeters of suspension travel, the Sensor competes with the new crop of longer travel 29ers.
GT's Sensor mirrors the proffile of its Force, but the Sensor frame is simpler, lighter weight and its geometry is more in keeping with an XC-style trailbike. The head angle is 68.5 degrees, with a low, 344-millimeter bottom bracket, and a roomy, 600-millimeter top tube (medium size). Travel is 130-millimeters front and rear and the Sensor Carbon Team uses a lighter, Fox 32 CTD Kashima fork.
GT chose the mid-size wheel reportedly to escape the unwieldy sensation that long-travel 29-inch-wheel trailbikes produce when pushing them around tight trails. Reportedly, the Sensor Carbon frame weighs 2.7kg (5.94 pounds) in the medium size with a shock - which should work out to complete bike weights in the 27-pound range. GT sells three versions of the Sensor in carbon and two in aluminum, so there should be one to fit the wallet of most enthusiasts. Sizes are X-small, small, medium, large and X-large. MSRP tbt.
Sensor Carbon frames are designed with a more conventional front section (upper left), but they share many common components with the longer-travel Force, like the PathLink and the AOS pivot system. Sensors, however, use a flatter shock curve to assist pedaling feel. Cables switch from external to internal routing as they pass by the bottom bracket.
GT chose e-thirteen wheels and Continental tires across the board for its 2014 trail and gravity lineups - which is a good thing, as both brands are pushing hard to impress hard core riders and, from the buzz out there, both are succeeding. Most riders will love how fast Conti's X-King tires roll, but the nature of GT's capable suspension and the Sensor's slackish frame numbers will encourage its owners to seek a more aggressive tread - up front, at least. Sensors get a slightly longer stem, but the bars are still out there at 760-millimeters, and GT keeps the stem-length constant by lengthening the top tube with each frame size. With the burlier Force in its range, GT chose 32-millimeter forks for the Sensor, quoting weight savings as its motivation. All but the least expensive Sensor model are equipped with dropper posts, however, with RockShox on top models and KS on its more affordable ones - all use internal routing. Most models have tubeless rims and tires and, once again, GT spec's triple cranksets on all Sensors.
GT offers the Sensor in both carbon and aluminum frames. The aluminum Expert (top) and the most affordable Elite are both sharp looking bikes in person. The difference in frame weight is 2.7 kg for carbon and 3.38 kg for aluminum with the same shock.
Pinkbike's First Impressions
Most trail riders should find the Sensor to be the weapon of choice for every situation but the most technical trails. With slightly larger wheels, the Sensor should roll over a lot of stuff that a 26-inch bike might take offence with, and 130-millimeter trailbikes are petty darn capable these days anyway. I am sure that GT is banking on a lot of riders who either have resisted the move to a 29er trailbike, or who have one and wish for the pump and pop of their old and now dusty 26er. You can't pry Hans Rey off of his, and by the way, GT makes a Hans Rey signature model in black and gold. It's based upon the aluminum Sensor chassis, but with lots of Kashima, a longer-stroke, 34-millimeter Fox CTD fork and it's decked out with Crankbrothers components. It looks sweet.
About AOS Suspension
GT's AOS suspension is wonderfully simple, but it would not function well if the close-coupled linkage and swingarms developed excessive bearing play or flex. GT puts dual bearings at each clevis pivot near the dropouts and pinch-clamps at each pivot location near the PathLink to ensure that the stiffness of the oversized, tubular pivot-axles is translated to the frame members. The suspension pulls on the PathLink as it compresses, which causes the bottom bracket to move rearward slightly. By tuning the pivot locations on the PathLink, GT's suspension designers can eliminate all of the system's pedal feedback - or tune in as much as they need to optimize the bike's pedaling feel.
GT Frame Engineer Jeremy Mikesell pulled apart a Sensor frame to show us the 15-millimeter pivot-axle system and to illustrate how the latest iteration of GT's Independent Drive suspension operates.
The PathLink must handle the stress generated by the strongest cyclists, so GT forges it in two halves and TIG welds it together to form a lightweight structure with a wide cross-section to maximize its rigidity. The upper end of the PathLink drives the shock. The lower end is pulled by the chainstays as the suspension compresses and somewhere in the middle - at just the right point - the PathLnk rocks back and forth on a frame-mounted pivot. Watch the GT's video below to see AOS in action:
See GT's New Suspension in Action
The Sensor's carbon lower suspension arm (left), with the 15-millimeter aluminum axle assembly removed. A look at the partially-disassembled AOS suspension showing the three pivot locations on the PathLink. As the PathLnk is pulled by the chainstays, it drives the shock forward and shifts the crankset slightly to the rear of the bike. It is a subtle action that is rarely, if ever felt by the rider.
GT uses a pair of sealed ball bearings in each side of the rear-dropout clevis-pivots to arrest any play that may arise in due to excessive wear. The chainstay member is carbon - including the clevis assemblies.
GT officially released the new Fury at the Fort William World Cup DH, where Gee and Rachael Atherton both rode it to victory. With a repeat performance at Vale De Sole, the Fury needs no further explanation. The news at Park City was that GT will be releasing four models of the Fury, with the top-range World Cup being spec'ed exactly as the team's, with the exception of its wheels. Shown below, from left to right, are the Team, Pro and Expert models. All share the same chassis as the World Cup model and sizes will be offered in X-small, small, medium and large. MSRP has yet to be decided for North America.
In case you wanted a closer look. (clockwise) The Fury begins with a Fox RAD air-sprung 40 fork, a look at the two-piece scissor link that is used to arrest lateral movement from the swingarm. Foes popularized the scissor link for the same purpose. The World Cup uses Shimano Saint drivetrian and braking components and Shimano Pro cockpit items. The Pro Stem is adjustable from 30 to 50 millimeters and the handlebar comes stock at 800 millimeters wide.