CUBE Bikes Stereo Hybrid 120 Pro 29  2014 Mountain Bike Review

CUBE Bikes Stereo Hybrid 120 Pro 29 2014

Reviews / Electric Bikes

CUBE Bikes 402,599

At A Glance

The Stereo Hybrid 120 from Cube is one of their latest incarnations of the electric mountain bike. It’s loaded with a Bosch Drive Unit Performance Cruise engine which pumps out 250 Watts of power. We’ve seen and heard a fair bit about e-bikes over in Europe where they have definitely taken a foothold. While arguably the jury is still out over here in the UK we were keen to swing a leg over the bike and see what the future may, or may not, hold!

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On The Trail

In the interest of a solid test I chose to ride the Stereo Hybrid around our local loop. It’s just over 14 miles, features some very steep ascents and plenty of fun downhill sections with some DH runs littered with jumps too. As a route I know well I have plenty of Strava times which I could compare the Stereo Hybrid segments with. In addition to that I put on the heart rate monitor so I could see how easy or hard I was working to ride the bike.

I don’t want to get into a debate about the pros and cons of an e-bike here, but as a philosophical kind of rider I can see the benefits. For unfit people and injured riders they can provide a great way of getting out on the trails. Personally I wouldn’t choose to ride one, but was that opinion about to change? I was expecting the ride to be easy and, if I am honest, perhaps a little uninspiring. Oh, how wrong could I have been!

The Stereo Hybrid has a few engine modes so you can dial in how much power you want to receive when pedalling, of course there is an “off” setting as well. I decided, as I am sure many people will, to just stick it in Turbo mode and see how it went. After all, what’s a Turbo mode for if not for abusing?!

I also said to myself that I would pedal as hard as I could, around the whole loop, in an effort to see how many Strava times I could beat, for the purpose of the experiment… As the bike is “Pedal Assist” this meant putting in quite a lot of effort, contrary to what some people may think.

As with many things in life, you get out what you put in and on the first climb the bike rocketed up the hill while I sweated away profusely mashing on the pedals like a loon. And so the ride continued in this manner, the speed at which it went uphill was simply astounding. Even on the steepest climb of the ride, which is normally a spin in the easiest gear, the Hybrid powered up at a consistent 12mph!

It literally rides uphill like you wouldn’t believe. I kept thinking the engine power would top out and the bike would slow down, but it never happened. The one downside is the bike is limited to around 16.5mph so on the flats you reach the maximum speed pretty easily especially with the engine. Of course you can turn the engine off, but then you are lugging all the extra weight around.

Heading DH was fun too, the 29er was exceedingly capable considering it’s more of a trail and XC styled machine with geometry to match. Yet over the steep rough stuff the bike handled it with aplomb. I did notice a few times the effect of the engine braking on the bike. When you don’t pedal obviously it will accelerate happily to 30mph, but try and stick a couple of pedal strokes in before a jump and the bike instantly feels like it tries to slow until you back off the pedals. This is due to the Pedal Assist being limited to 16.5mph, as mentioned. It won’t brake hard, but the engine will try to gradually get the speed back down to its maximum as you pedal. Once you get used to it and come off the pedals, or indeed turn the engine off, this of course isn’t an issue. However, it is worth bearing in mind - there was one alarming moment as I went to mash the pedals as a large double approached and the bike felt like it was slowing when I needed it to do the opposite.

When I got back and downloaded the stats from the ride the KOMS and PB’s came flooding in, the Cube was faster over pretty much every section of trail. Sometimes not quite as quick on the pure DH sections, but certainly wherever pedalling was required it was quicker.

Whenever the trail went uphill it smashed the times by serious margins. On the toughest climb of the route which I can normally get up at about 7mph it flew up at 12mph and took nearly a minute off my time. I took the KOM by over 30 seconds and I know there are some serious XC whippets who grind that climb for fun.

Perhaps most telling though was that the 14 mile loop that I can normally ride in just under 2 hours I smashed in 1 hour and 18 minutes. That’s a serious amount of time to shave off a ride! Even more interesting was that I was blooming knackered. I had approached this ride fast, putting in as much effort as I could and despite having the engine I was blitzed.

Looking back at the heart rate information was even more telling, for both rides I had the same average heart rate 144bpm, and the same peak heart rate 178bpm. I’d essentially been working just as hard on the electric bike as I had on the normal ride. My average speed was 9mph without the engine, and 12mph with it. I’d ridden just as hard, but the engine had helped me to go faster.

This meant I could get the same number of miles under the wheels in less time. Time is something that is incredibly precious to all of us. I was really surprised by all this data, it wasn’t what I was expecting at all. Of course I knew the bike would be quicker uphill, but I hadn’t thought it would be quite so fast. I really didn’t expect my heart rate data to be the same, and I hadn’t predicted it could be such a workout!

I also really didn’t expect to enjoy it as much as I did, it was ridiculously fun and if I was presented with the same opportunity to ride the e-bike again, then I would jump at the chance! Of course I could have just cruised around, or taken it easy, and I guess for an unfit rider they could take the e-bike and keep up with more regular riders who have no engine without breaking too much of a sweat.

You get out what you put in as they say…

The battery life was pretty good, in full Turbo pedal mashing mode we got between 30-40 miles out of the bike depending on the battery, of course it has other modes that can give you more battery life, but when you see the word Turbo, you tend to go for it! One factor which we think will keep these bikes away from the mainstream at the moment was the weight, at over 21kg the bike is heavy, it actually fell through the box when it got delivered and was a pig to lift over gates and stiles. This makes it pretty unpleasant to pedal when the engine is off, especially uphill. However, the bike feels very stable at speed and exceedingly planted when riding downhill.

In the future this weight will obviously just keep coming down, We’re pretty sure there will come a time when the engine and battery won’t have a huge effect on the overall weight of the bike, and that is when these things will truly have their day. For the moment they are just that little bit too heavy to tempt me away from my traditional leg-powered steed on a permanent basis…for now at least…

Tech Heads

What makes the Hybrid such a capable bike are the high quality components that have been lavished upon it. Often with e-bikes the money is spent on the engine and the rest is a mishmash of parts to keep the price down.

The frame is a specially designed affair to accommodate the engine and the battery as neatly as possible. It’s a full High Performance Aluminium (HPA) affair with advanced hydroforming. Suspension is taken care of by Fox with a 120mm Float 32 29 CTD up the front and a Fox Float CTD BoostValve looking after the 120mm of rear travel.

Drivetrain is a very capable Shimano XT set up with of course a specific crankset that is mated to the Bosch 240 watt engine. It all worked perfectly and we had no issues here at all. The same can be said of the very dependable Shimano Deore brakeset. Our ride was fitted with a very useful Reverb seatpost, it’s not listed on the spec sheet, but it did come in handy especially as you get up the hills so quickly. The ability to drop and raise the saddle on demand and quickly was great.

Cube Stereo Hybrid 120 Pro 29 18”

Seat tube 460mm
Effective top tube 588mm
Head tube 120mm
Chain stay 504mm
Wheel base 1190mm
BB height to Hub -40mm
Head angle 69°
Seat angle 74°

Weight w/o pedals 21.5kg


E-Bikes have certainly come along way, the Cube was extremely fun to ride, fast and nimble on the climbs the power was limitless! Downhill the bike handled things well and the extra weight was only really a burden when lifting the bike over fences. A surprisingly good workout too, the bike isn’t a cheat by any stretch, if you put the effort in you’ll be rewarded with some very engaging performance! I’m not selling my leg-powered machine just yet, but if you are in the market for an E-Bike then the Cube is a pretty darn good option. If you’re sceptical about e-bikes, maybe reserve judgement until you have actually ridden one. We were surprised at just about every step of the journey!

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This review was in Issue 30 of IMB.

For more information visit CUBE Bikes


By Rou Chater
Rou Chater is the Publishing Editor of IMB Magazine; he’s a jack-of-all-trades and master of none, but his passion for bikes knows no bounds. His first mountain bike was a Trek 820, which he bought in 1990. It didn’t take him long to earn himself a trip to the hospital on it, and he’s never looked back since. These days he’s keeping it rubber side down, riding locally and overseas as much as possible.

Tried this? What did you think?