The matt black stereo is striking yet discreet. Equipped with the finest parts, the Twentyniner makes you want to ride uphill. The marathon bike is actually very light. However, there is no shortage of lightweight components. Carbon wheels, Sram XX1 drivetrain in combination with the new Race Face "Next SL" carbon crankset, a carbon seat and a lightweight Syntace/Cube cockpit are not the kind of parts that cause the scales to go through the roof. The frame has some ingenious details. To install a dropper post, the cable clamps can be opened and split for a second cable. This cable can be pulled semi-integrated through the prepared seat tube. The remaining cables and lines run from the cockpit into the down tube where they exit through a large, sealed outlet in front of the bottom bracket shell and are routed from there to their destinations. The carbon fibers of the down tube are generously covered to protect them from stone chips. The Stereo's rocker arm is impressive. It is hollow, made entirely of carbon and does not require any aluminum inserts. The rear bumper is a Fox "Float CTD" shock absorber. At the front, the new "Sid XX Solo Air" from Rock Shox is relied upon.

Confirmed strengths
Finding the right position takes a little more time than usual. Once the optimum riding position has been found, this marathon bike quickly feels comfortable. It can be propelled with ease and confirms the expectations of the uphill performance. The carbon saddle with the thin padding, which was developed in-house by Cube, also impresses with amazing comfort - at least on the tester's buttocks. The Cube masters steep climbs over roots or on loose ground very well thanks to its upright riding position. The XX1 drivetrain fits the range of use and the Race Face cranks are also impressive thanks to their stiffness. The Fox shock is almost free of pedal influence and can be ridden uphill in "Descend" mode without any problems. On gravel and asphalt climbs, however, the "Trail" or "Climb" mode is recommended, especially if you get out of the saddle in between. When setting up the suspension strut, 25 percent negative suspension travel is considered comfortable. This means that the shock still provides sufficient feedback to the rider. This characteristic comes into its own on flowing trails in particular. The shock absorber does not sag when accelerating out of corners and therefore does not make the bike sluggish. The Rock Shox suspension fork impresses with its sensitive response. Here, 25 percent negative suspension travel also appears to be optimal and even with a softer setting, the fork does not collapse if the rider hangs on the brakes for longer.

Tire limiting factor
The wheel combination of Reynolds carbon rims and DT-Swiss hubs and spokes cut a fine figure. The inner profile of the rim has a raised edge so that the tire cannot slip inwards even with low air pressure. However, this rim makes it difficult to change a flat tire. Strong fingers or tire levers are indispensable in this case. With the tires, Cube has hit the lightweight design nail on the head. However, the "Dirty Dan" and "Thunder Burt" tires from Schwalbe in the lightweight version do not correspond to what the bike is really capable of. Good for gravel roads, the tires don't really suit such a potent marathon bike - weight or not. More stable tires would generate much more safety and riding fun. Apart from that, the "Stereo" rides well downhill. Even difficult descents can be mastered well. When things get rougher, the 120 millimeters of suspension travel together with the 29-inch wheels help. Weaknesses become apparent in tight hairpin bends. Because the rear triangle is not quite as short, it takes a little more physical effort to maneuver the bike around tight corners.

Conclusion
With the "Stereo Super HPC 120 SL 29", Cube brings a marathon racer that opens up a much wider range of use for the owner. However, with a tire update and a slightly shorter stem, the riding performance of this bike could be increased even more.

Specifications

Manufacturer:
www.cube.cu

Test report published in issue 01/2014 of Ride Magazine.