TESTED: Cube Stereo Hybrid 140 HPA 27.5

E-Bikes, like them or not, are here. For those of you not 100% sure on what an e-bike is, it’s a bike that has an electric motor integrated into the drivetrain which gives power only when pedals are activated. This is commonly called ‘pedal assist’. Unlike electric bikes, there is no simple on switch which provides full power with no input, you do have to pedal them.

There are also various state wide and worldwide regulations regarding power and speed output and as such the bike industry has decided that a maximum speed of 25kph cuts the power and you are pedalling on your own. Out of the range of e-bikes currently available it seems that there are 2 power trains that have been widely adopted by main players in the industry, those being the Shimano STEPS system and the Bosch system.

FIRST IMPRESSIONS

Our particular model, the Cube Stereo Hybrid 140 HPA 27.5 Race 500, to give it its full name, utilises the Bosch system which has the motor built into the frame around the bottom bracket area and a detachable rechargeable battery neatly attached to the down tube, which Cube call the Powerpack. Activation of the system is done via a control pad on the left hand bar with settings for Eco, Sport and Turbo and also a Walk setting which are displayed along with speed, mileage and charge on an LCD display.

The e-stereo is a dual suspension bike, described as an, 'All Mountain Hybrid', featuring 140mm of travel front and rear, both activated by Fox units attached to the aluminium, HPA Ultralight, Advanced Hydroform, Triple Butted, aluminium frame with an ETC 4-Link, suspension system.

The drivetrain is the ubiquitous Shimano XT 11-speed which as you can imagine, works flawlessly. The only obviously striking difference being the tiny front drive ring which only has 16 teeth. This may lead you to believe that the bike is going to be terribly low geared but fear not, the crank and motor system is a planetary geared unit with one full rotation of the cranks giving the equivalent of around a 32-tooth ring. Battery charging is completed by detaching the battery and charging it on the supplied lead through the mains. A full charge, depending on what setting you are using can get you a reliable 80kms before the e-bike just turns into a really heavy bike. If only using it on the Turbo setting you’ll get a bit less. The battery clips and locks into place in the downtube using a simple key system to prevent theft.

So about that extra weight. Yeah. It’s a lot, the whole bike comes in at about 24-25kgs, double the weight of my regular ride, so yes, it is noticeable, even more so when maneuvering the bike when not riding, putting it in the truck is an effort  and hanging it on a storage hook is basically impossible.

ON THE TRAIL

On the trail, flick the unit on and the weight issue becomes less of a worry, it is quite a strange sensation to pedal with the pedal assist engaged. The bike starts to fly along, seemingly increasing its output the harder you pedal. Riding up smoother singletrack and switchbacks will result in previously unheard of speeds that almost drown out the inner voice saying, “you’re cheating!” Gear selection and changes are the same as any other bike, however, as soon as you hit 25km/h, the power assist switches off, and you are back in really heavy bike mode. And it’s surprising how often you do go over 25km/h, any level fire road or bitumen will soon see you having to work and even good flowy sections of singletrack will have the power assist clicking in and out. Annoying? Yes.

With all the extra weight, bike set up is also a bit different, expect to run a lot more air pressure in your forks and particularly in your rear shock to compensate for the dead weight. I can see that the main suspension manufacturers will be bringing out e-bike specific shocks  in the near future, with much higher compression settings. A downside of having to run higher pressure is that in less aggressive trail the suspension felt very clunky, I found that running the rear shock in the open position complemented the general balance of the ride and because of the power assist, the soft setting didn’t impede acceleration with the added boost of the motor. Interestingly, its also a bike that greatly benefits from riding clipped in rather than the often more fun flat pedal. The combination of the planetary geared cranks, power assist engaging and disengaging, and the extra weight having a negative effect on the compression settings, can make for a clunky ride.

Add the all or nothing stabbing nature of flat pedals and this can further enhance the negatives of the pedal-assist. Conversely,  having a smoother and more consistent pedalling style where you're capable of controlled upstroke helps minimise the clunky effect. Pedal assist only works when pedalling, when riding flats you develop a carrying speed without pedalling technique which obviously is ineffective on the e-bike.

The rest of the build is a predictable and generally reliable set up, Fox 34 Rhythm forks with 3-position micro adjustment and a Fox DPS EVOL damper on the back again with 3 position settings give a solid and reliable platform. Cube branded rims on Shimano Deore hubs keep you rolling with tubeless ready Schwalbe Hans Dampf 2.35” tyres providing grip, most of the time! The 11-46 cassette is a nice addition to expand the 1×11 range.

Cube's own brand non-dropper post and 740mm bars and 70mm stem round out the handling and are more in line with a long travel Cross-Country than All-Mountain bike. Braking is completed by Magura MT Trail, hydraulic disc brakes running 180mm rotors front and rear with an excellent 4 pot front caliper powered by the not so excellent resin levers and lever bodies which I found to be very flexy and give an inconsistent feel, particularly in the hot weather.

When riding the factory specifications of the bike gave a bit of a mixed message as to its primary use, and therefore its primary buyer. On face value it’s a 140mm travel bike, so its more of a trail bike? Yes and no. Having no dropper post supplied greatly reduces its trail bike abilities, I was fortunate enough to borrow one from Damo at Nicks Cycles and I’m sure that anyone buying this bike will soon be investing in a dropper. The head angle of 67.3 isn’t particularly slack for a bike of this travel and designed use and the chain stays, at 468mm are positively gigantic by any standards.

To give a broader objective review and to address some of the reasons being marketed for e-bikes I let a range of other people ride the E-Stereo. From  non-riders to weekend hacks, the bike came back with mixed reviews. For absolute non-riders, just riding around on predominantly flat terrain the bike provided plenty of smiles and encouragement, again until I nudged them past 25kph…

A concept that is being heavily marketed toward e-bikes is that of providing a bike to the new rider, to experience mountain biking with their mountain biking friends and bypassing the inherent need for a higher level of fitness. I tried this. I took my beginner friend on some good singletrack on the South Coast, a quick car park test gave the new pilot a ring of confidence with the assisted power available so we hit the trails.

Almost immediately the compensation of the assisted power was put aside by the new rider not having the trail skills to negotiate what was realistically basic cross country terrain. Add a very heavy bike with moderate geometry to the mix and I was soon at the conclusion that this beginner would be better off on a regular bike. Other experienced riders also came back with mixed reviews, yes, blasting up fire roads is a hoot, but is riding up fire roads really the highlight of the thing we call ‘mountain biking’?

FINAL THOUGHTS

In my opinion, the Cube E-Stereo defines the compromises we must make when choosing a mountain bike. Many e-bikes make the not-so great bits of riding easier but can compromise what most of us find the most fun in riding, that is railing singletrack, carving berms, drifting flat corners and punching the odd gap. E-bikes like the Merida 160 900e tested last year have nailed it, but it's not to say any e-bike will deliver the same experience.

However, choosing a bike is always a compromise, where you end up trading one quality for another. Be it in agility versus stability, or climbing prowess compared to all-mountain durability. And as such, looking at an e-bike like the Cube Stereo Hybrid presents another choice which is a compromise. Your time to ride may dictate whether you are better served with a 140mm trail bike, or something from the e-bike range like the Stereo I tested. For me, the compromise in weight and handling isn't offset by assistance. My 30 years of cycling has taught me that working hard for the descents is part of why I ride, and I want a bike that lets me get the most out of the descents. But for different riders with varied reasons to ride, and on terrain not like the trails I ride – all these elements create a different decision process.

And in that instance, the Cube Stereo Hybrid does offer a 140mm trail bike (the geometry prevents me thinking of it as all-mountain capable) with moderate geometry that offers up few surprises with the parts spec and handling. I suggest you don't leave the store without having a dropper post fitted – and if you're just not sure on whether an e-bike is for you anyway, ask your dealer when the next test ride event might be, and find out for yourself whether an e-bike suits your riding.