If you squint, the Cube Stereo Hybrid 140 HPA Pro 500 27.5 looks like the regular Stereo 140 that it’s based on. So it’s still got 140mm of travel but neatly tucked into the frame is a Bosch Performance Line CX electric motor that delivers four levels of pedal assistance.

Cube has one of the biggest electric bike ranges of any of bike company – there are four models in the Stereo Hybrid 140 27.5 range alone, there’s also a 120mm and 160mm model and one with 27.5 Plus tyres, so plenty of electric bike choice.

>>> The best electric mountain bikes

Motor

Cube packages the Bosch Performance CX electric motor very smartly into the triple butted aluminium frame, with the Bosch Power Pack 500 resting neatly on the extra-wide down tube.

The motor provides 75Nm of torque and there are four levels of assist, Eco to Turbo, the latter providing a whopping 300% of assistance. You can, of course, turn off the assistance, but at 22.39kg (49.33lb), you probably won’t want to.

The battery pack can be charged on or off the bike and it will charge to 50% capacity in an hour, and is locked to the bike for security.

The Bosch Intuvia display isn’t as advanced or as compact as the newer Purion unit, but the centre mounted display is clear and easy to read, and the remote switch, positioned next to the L-hand grip, lets you easily switch between assist levels.

It even suggests gear changes based on your cadence, and you can track your ride with range, distance, speed and other key metrics, just by pressing the information button on the remote control.

The motor is quite noisy and as it does rather detract from the quiet buzz of tyres on dirt that usually accompanies a mountain bike ride, and other trail users will certainly hear your approach. Which isn’t necessarily a bad thing.

Suspension

Despite having to accommodate the quite large battery and motor, Cube has managed to retain its familiar four-bar suspension, with a long rocker link activating a vertically mounted Manitou Radium Expert shock delivering 140mm of progressive suspension travel.

The shock has adjustable rebound, but we didn’t find much use for the lockout lever – you don’t spend much time climbing out of the saddle on an electric bike, and the tune on the shock is sufficient to keep it all under control.

Keeping the Manitou theme going is the Manitou Mattoc 140mm fork. While the rear suspension worked admirably on rough terrain, the Mattoc felt lethargic and lacked the quality of damping we’ve become accustomed to from other fork manufacturers.

It wasn’t helped by the restricted range of rebound damping, and you’ll want to run higher air pressures than the recommended settings to prevent excessive dive under braking. Chassis stiffness of the fork is commendable given the overall weight of the bike.

Components

This is the second cheapest in a four bike range and you get an 11-speed groupset based around a Shimano XT 11-42t cassette, which provides a good range of ratios for getting the bike up most hills, with the Turbo assist mode counteracting any shortfall of range on the steepest climbs.

A XT ShadowPlus rear mech keeps the chain taut over rough terrain, with a matching XT shifter providing crisp and accurate shifts, helping you to maintain the optimum cadence.

The Magura MT2 hydraulic disc brakes are budget offerings but the levers have a nice shape and feel. The 180mm front rotor occasionally struggled to slow the momentum of the Cube, so 200mm rotors front and rear would be a better option.

A Cube-branded 740mm aluminium handlebar was a good width but the stem felt too long – switching to a shorter one significantly improved the handling.

While the components proved adequate, without doubt the biggest omission is the lack of a dropper post, so you might want to budget for an immediate upgrade.

Performance

With the suspension tuned and the cockpit tweaked, the Cube really starts to make a case for itself on moderate, fun trails, but it rapidly gets out of its depth on steep, fast and technical terrain.

The potential is there, it’s a very stiff frame and rear suspension is really effective at soaking up the hits but the Hans Dampf tyres aren’t the best at keeping the bike in check at the higher speeds it’s capable of.

But it’s in the geometry, or specifically the reach measurement, where the Cube loses grounds to its more modern rivals. Yes, the bike is available in four sizes, but the even the size 20in tested has a short wheelbase and short reach – a full 30mm shorter than the Trek Powerfly that we tested in the September issue.

Along with the 67-degree head angle, the result is a riding position that feels quite upright and short, which means it doesn’t feel all that stable or planted on the descents and through challenging terrain that’s littered with holes and roots.

You can cover a lot of ground quickly with the Cube and not break a sweat in the process. Power delivery from the Bosch motor is smooth and you can cycle through the four assistance modes to balance the input of power dependent on the terrain.

It winches up climbs with astonishing pace but it’s through fast flowing singletrack that the Cube lacks the liveliness and poise of a regular mountain bike.

The extra weight requires an adjustment in riding style too; you can’t pop the bike around the trail or use slight weight transfer to balance the bike through a corner – even lifting the front wheel to manual obstacles was tricky due to the long chainstays and the extra weigh of the battery.

It’s very much a wheels-on-the-ground approach so if you like to float the bike over the trail, the extra weight will dampen your enthusiasm. Still, at 22.39kg (49.33lb) the Cube is inline with other electric bikes in its class.