Arc8 introduces the new Extra, an enduro bike with carbon frame, 160mm of travel at the rear, 160/170 at the front, 29/29 or mullet format, and that can accommodate both coil and air shocks. I had a chance to try it for a day on the Graubünden trails in Thusis, using the new Story Lodge as a base.
The most significant feature of the Arc8 Extra is its suspension system, called the Dual Pivot Suspension System (Slider System), the same one I had tested on the Arc8 Evolve. The advantage of this system is described this way by Arc8:“In our dual pivot suspension system, a slide replaces the traditional linkage, resulting in a suspension that can be controlled with extreme precision. This system is known for its sensitive initial response and then smoothly releases the travel, providing a controlled feel throughout the suspension travel. With a traditional linkage and a long-stroke shock, the linkages must rotate significantly. This causes the force not to follow a direct path to the shock absorber, making it increasingly difficult to achieve an optimal “drop rate.””
The system is very progressive toward the end of travel, which also makes it suitable for coil shocks.
Another advantage of our dual-pivot suspension system (Slider System) is the ability to independently adjust progression, travel and anti-squat. When the slide rails are moved up or down, only the travel is affected, while the progression is affected by the angle of the rails. To change the anti-squat, the main pivot point must be offset. This allows us to achieve a very sensitive response in downhill and a relatively anti-squat performance in uphill. On the new Extra, we have an anti-squat value of 104 or 102% with a sag of 30 or 35%.
From the Evolve, the Arc8 Extra also takes the high chainstays that flex. A solution not seen very often on a bike of this range, and feasible only by keeping the top of the rear triangle rather thin. Speaking of chainstays, they get longer as the size increases, to keep the Extra’s behavior constant.
The Extra has a storage compartment in the down tube that I could not test because the cover was not yet ready at the time of the media presentation. Great idea avoiding the cable routing inside the headset, as was the case with the previous model.
Geometry
The geometry varies depending on whether the Extra is in Mullet or 29 format (modifiable via flipchip), and on the fork you decide to mount. The very steep 78° seat anglestands out, as does the very open head angle. Compared to the previous model, the stack has been raised to give more confidence and control on steep descents. Three sizes are available.
Arc8 Extra: first riding impressions
The test ride included several downhill trails with shuttle ascents and a pedaled, partly steep section. The terrain was loam dotted with nice rocks embedded in the ground and dry conditions. I was given the mullet model with 170mm fork and coil shock absorber in size M (I am 179cm tall). Uphill it pedals very well thanks to the steep seat angle and the rather long chainstay, I am convinced that in the 29/29 configuration this feature would stand out even more not only because of the larger tire footprint, but also because of the 12mm longer chainstay. Even without locking out the shock, I did not feel any noteworthy bobbing.
Since this is an enduro bike, the Arc8 Extra’s preferred terrain is downhill, even given the coil shock absorber of the build I tested. I expected a softer suspension, but instead found it to be very responsive and sustained in the mid stroke, as if the character of the Evolve XC bike had been transferred to an enduro bike. I checked the sag, which was at 30 percent, and where the end-of-stroke pad was, to make sure I used all the travel well and had the correct spring hardness (I probably would have switched to a less hard spring in a long term test). On the other hand, flexing the high chainstay is a precise choice that will please those who are looking at the stopwatch and a very “sporty” bike that is easy to pump over obstacles and bunny hop.
The saddle position is nice and centered, with just the right amount of front end that gives confidence on the steep and doesn’t require you to move your torso too far forward, making the bike easy to turn, also aided by the 27.5 wheel at the rear.
In all the builds we find Shimano brakes and drivetrains, with good value for money, considering that Arc8 now sells both online and through stores. The one I tested was the Extra Coil XT Fox 38 Factory 170mm (€7,499), the others can be found here.
Compared to the first model, which was quite successful partly due to its very competitive price (you can still find it on offer on their site), you have to dig deeper in your bank account.
