The GT Force Carbon Pro LE is a ground-up redesign with high-ish pivot idler LTS suspension delivering 160mm travel, with RockShox Ultimate level suspension giving maximum control and combined with a 170mm Zeb fork with a SuperDeluxe shock. It’s part of a trend towards high-pivot idler suspension, something that’s becoming increasingly prevalent among the best enduro bikes.

Need to know

• Mid-pivot idler design meets LTS suspension to deliver 160mm travel
• GT marries a carbon front end with an alloy rear end
• RockShox Ultimate level suspension comes on the top-end Carbon Pro LE
• Flip-chips in the rear dropouts offer two chainstay lengths for tweaking weight distribution

Giving it some – the GT Force Carbon Pro LE in action

GT’s approach to frame and suspension design

GT has never shied away from suspension development. Its early designs employed a high single-pivot design dubbed RTS, before transitioning to LTS, a classic 4-bar configuration.

In recent times GT hung its suspension hat on iDrive, again a high single-pivot design, but this time with a floating drivetrain. When GT introduced the updated Sensor and Force platforms in 2018, it circled back to the glory days of LTS with a popular rocker link configuration.

Fast forward to today and the latest Force is a 29er enduro bike that retains the LTS suspension, but the links have been reconfigured to produce a 160mm travel mid-pivot idler design. It’s referred to as a mid-pivot design, because the pivot point (in this case virtual) is higher than a conventional design, but not as high as, say, the Forbidden Dreadnought.

As such, the axle path on the GT Force isn’t 100% rearward. Instead, it’s rearward for the first 60% of the travel then moves forward for the last 40%, never going forward of the starting point. It’s basically as close as you get to a vertical axle path.

The all-important idler

The advantage of this approach being, you don’t get such dynamic changes in the geometry as the suspension compresses. Also, because the pivot is lower the idler doesn’t need to be as high, so the chain raps around the chainring more, eliminating the need for a lower chain guide and the associated increase in drivetrain resistance. GT’s configuration also provides stacks of clearance between the chain and chainstay, so there’s zero chain slap.

For the latest Force, GT blends a carbon front end with an alloy rear to provide four sizes, where flip-chips in the rear dropouts make it easy to change the weight distribution of each size. In the short setting the chainstays measure 434mm, growing by 10mm in the long setting. We ran the size L test bike in the long setting to better load the front end. Also with its 472mm reach, it isn’t super long so by extending the rear end you can make the bike feel bigger. 

Suspension

Being the flagship LE model, the Force comes equipped with premium suspension; a 170mm travel RockShox Zeb Ultimate fork and Super Deluxe Ultimate shock. The fork is pretty sensitive to small changes in spring pressure so it’s worth getting a digital shock pump to really fine tune the sag. Too soft and the Zeb feels like there’s a lot of resistance in the rebound circuit when popping the front end up. Too hard and it starts to get harsh.

Get the spring rate just right though and the Zeb will let hard charging riders dive into the roughest terrain with supreme confidence. 

Force Carbon Pro LE features a rocker link

The 160mm rear suspension is also sensitive to set-up. The shock has three volume spacers fitted, so if you’re struggling to achieve full travel, removing some of the spacers is one option, especially if you’re running 25% shock sag for improved pedalling efficiency.

The other approach, and the one we’d recommend, is to run the rear shock with slightly more sag, ideally 27-30%. This means the bike will have less anti-squat, so it won’t pedal as well, but it increases the sensitivity of the suspension while retaining enough support for railing berms and landing drops.

Rockshox Zeb up in yer face

Components

If you sit between recommended sizes on the GT it’s worth noting that the size L bike comes with a 200mm TranzX dropper post, so we pretty much had the post slammed in the frame to achieve a 740mm saddle height. GT has also opted for a smaller 31.8mm clamp bar, and while that’s perfectly fine, it looks disproportionately spindly when married to the beefy Zeb fork and chunky carbon front end.

We loved the classic mushroom design of the Charge lock-on grips, but the Charge Scoop saddle has too much curvature for our linking and leads to pressure points where you least need them. 

SRAM Code RSC brakes provide stopping power

And even if the Charge Scoop isn’t our preferred choice for big days in the saddle, with an 10-52t SRAM Eagle cassette the GT has the gearing for it. Get up into the lower gears however, and it’s noticeable how much noisier the idler gets. This seems to be a result of the idler position being slightly more rearward, which increases the chain angle relative to the cassette and it will be even worse in the short chainstay position. 

SRAM’s Code RSC brakes are firm favourites of ours, but in wet conditions we found that the stock brake pads fitted to the GT took longer to dry out so you have to brake sooner than expected to scrub speed, even with the 220/200mm rotor combination. 

Performance

Getting the GT Force to feel balanced took us longer than expected. Run more than 27-30% of sag on the shock and the rear suspension lacks the support needed for climbing and railing turns. Go too far the other way and distinct loss in sensitivity makes the bike feel too reactive and harsh. So there’s a relatively small window where the GT Force feels really good. We found 27% sag to be optimum, and the Force rewards you with a balanced stable ride, good small bump sensitivity with ample grip and support. 

We tested the GT Force Carbo Pro LE in a range of conditions, and against the Forbidden Dreadnought

In fact, for an idler bike the Force feels remarkably normal, and that’s intended as a complement. Even in the long chainstay position it’s super easy to pop the front up, square off turns or simply boost jumps. We even lowered the stem height to better load the front end on flatter trails, which also makes the cockpit feel a little bigger. No bad thing. 

For an idler bike the Force feels remarkably normal, and that’s intended as a complement.

So what’s the advantage of the idler? At Bike Park Wales we noticed how easy it was to pedal over choppy terrain, even with flat pedals. The bike also felt less fatiguing on longer descents like Root Manoeuvres. How much of this is down to the lower anti-squat numbers or reduced pedal kickback is hard to parse out, but the benefits are real.

Would higher anti-squat numbers improve the pedalling response of the Force? Most definitely, but it would also benefit from a wider set-up window so you can use the sag to tweak the dynamic geometry and suspension response without compromising pedalling.

Looking for an alternative high-pivot idler enduro bike? Check out the Forbidden Dreadnought XT.

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