First look: New GT Sensor and Force 27.5 bikes
Originally posted on June 18, 2013 at 18:54 pm
By Eric McKeegan
Fresh of the introduction of the redesigned Fury downhill bike, GT Bikes invited journalists from all over the world to sunny Park City, Utah, to ride the new Force and Sensor trail bikes. Both bikes are fresh designs, based on a new suspension system and 27.5 wheels.
The big news at the launch is that new suspension system—Angle Optimized Suspension or AOS. Most riders are familiar with GT’s i-Drive, and the new system works in a somewhat similar fashion. The heart of the system is the Pathlink, a hollow forged aluminum link that houses three pivots and the bottom bracket.
Much like i-Drive, the bottom bracket is carried neither on the swing arm, nor the main frame. This allows GT to use a very high main pivot to provide an axle path that moves backwards at first to help get the wheel out of the way of bumps. Normally a very high pivot would create a ton of chain growth and cause the suspension to lockout under pedaling forces. The Pathlink allows the bottom bracket to move backwards a tiny bit to help control chain growth and keep the suspension active under power. The Pathlink is also a much simpler set up than i-Drive
In theory, a bottom bracket that move around while riding sounds dreadful. In practice I never noticed, and neither did a single journalist that I talked to. What I did notice was a suspension system that sits right in between the platform valve dependent systems (FSR, most single pivots) and the mini-link systems (dw-link, VPP).
The AOS system pedaled well enough to ride around all day in the Descend position on the Fox rear shock, which is a good thing, since the platform lever is very low on the bike, and hard to flip in any kind of rough terrain. Standing pedaling wasn’t up to the standard set by dw-Link, but AOS was much better at small bump compliance. Generally I’d say the suspension stayed out of the way, doing its job with so little fuss as to be forgettable. This is a high compliment.
Geometry for both bikes is modernized for the new-school trail rider: Bottom brackets are lower, top tubes and front centers are longer, and rear centers are tightened up a touch. All good things in my book. I scraped pedals a few times, but that is a trade-off I’m willing to make.
Sensor
The first day had my group out on the 130mm Sensor. We rode the pretty fancy Carbon Pro model with a Fox 32mm fork, Shimano XT drivetrain, Formula Brakes, E13 wheels, and somewhat unexpectedly a Race Face triple crank. With just about everyone else dropping to one or two rings, GT is sticking with the triple. This bike is squarely aimed at the global market, where GT claims 75 percent of mountain bike sales are still triple crank bikes.
The first ride of the day was in a big group on rolling terrain mixed with some rocky bits. The Sensor ate this up with little fuss. It felt like a good trail bike should, agile, efficient, and comfortable. After lunch, some of the more adventurous among us ended up riding some more technical trails, including some black diamond downhill trails. While I wouldn’t say the Sensor ate these up too, it wasn’t at all upset. The dropper post was really the equalizer. Getting low and back on the steep stuff allowed me to roll the Sensor over some pretty chunky drops.
There will be seven Sensor models for 2014. Three with carbon frames, three with aluminum frame, and a Hans Rey Signature model. The signature model’s alloy frame is decked out with his sponsors’ components, including wheels and dropper post from Crankbrothers, and SQ Labs saddle and grips. Most importantly, at least to me, it also gets a 140mm travel Fox 34 fork and beefier tires. I’m going to go out on a limb here and say that bike is going to rip.
A quick scan of the geometry charts for Force reveals some substantial differences between the carbon and aluminum frame. A medium carbon frame has a 68.5-degree head angle, 23.7-inch toptube, 17.3-inch chainstays, and a 13.2-inch BB height. The alloy model is notably different, with 69.5-degree head angle, 23.2-inch top tube, 16.7-inch chainstays and 13.1-inch BB. They are big enough for sensitive riders to notice. I’m wondering if the short rear end of the alloy frame would bolt up the slacker and longer front end of a carbon model…
I’ve got emails in to GT to check into the how’s and why’s of the geometry differences, as well as prices and availability.
Force
Day two was Force day. With 150mm of travel, bigger tires and slacker angles, the Force certainly looked the part of a ripping all-mountain/enduro bike in the short riding clips we saw of the third Atherton, Dan, shredding trails on his Force. I’ve got nowhere near the shredditude of Dan, but I was happy to slip on some Hans Rey Signature IXS kneepads and give it go.
The big morning group ride involved quite a bit of rolling terrain, climbing and not so technical single track. I was pleasantly surprised the Force lost little to the Sensor in pedaling efficiency. Once things got steep and more technical, the stiffer fork, longer travel, and slacker angles felt right at home.
After lunch a few of us headed out to find steeper terrain and ended up on a double black diamond run. Probably a touch past the design intent of the Force, but a good chance to see how the bike worked when pushed hard.
On the steep and chunky trails, the Force was happy to slide around and down the loose, dry terrain of Deer Valley resort. As we got closer to the bottom, the trail became a little less steep, and I was confident blasting though the bumps, even riding blind into the dust cloud from the riders ahead of me.
As of now, there are only three models of Force, all using a carbon frame. I would expect an alloy model to be added soon, but GT wouldn’t confirm or deny when or if that might happen. The carbon models are all pretty spendy, but official prices are also TBD.
Fury
While the bikes were the big news, the timing couldn’t have been much better. The weekend before the media camp, siblings and GT riders Rachel and Gee Atherton both pulled off wins at the Fort William World Cup race. After a day of riding on Saturday, we gathered to watch the second round of the World Cup from Val de Sole, Italy.
Ms. Atherton had already taken the win in the women’s race, and the dozens of bike scribes and GT employees were on the edges of out seats for the men’s race. As the top qualifier Gee was slated to run last, and we all watched as the times dropped, and the hot seat changed hands many times. Gee pulled of the win on the powdery, technical Italian course, and much rejoicing occurred among GT employees and journalists alike.
The Athertons are winning on the newly redesigned Fury with a much more modern (read: slack) geometry than the previous model. The frame is also now alloy only, but it drops 300 grams over last year’s carbon model. I didn’t get a chance to ride one, yet, but I’ve got a request in for a review bike as soon as they are available.