Brose, Bosch, Shimano, Fazua, Panasonic, Giant e-bike systems… which has more power, which has more battery punch, which is more reliable? Our guide to e-bike motors has the answers. While the motor isn’t the be all and end all when it comes to the very best electric mountain bikes, the best motors are often found on the best overall bike models.

E-Bike motor torque and max power at a glance

• Brose Drive S-Mag: 90Nm/565w
• Panasonic GXO: 90Nm
• Bosch Performance Line CX: 85Nm/600w
• Shimano EP8: 85Nm
• Giant SyncDrive
• Yamaha PW-X2: 80Nm
• Shimano E8000: 70Nm
• Shimano E7000: 60Nm
• Fazua Evation 1.0: 55Nm
• Specialized SL 1.1: 35Nm/240w
• TQ HPR50 (Trek Fuel EXe) 50Nm/300w
• Forestal/Bafang Eondrive 60Nm/400w
• Fazua Evation Ride 60 60Nm/450w

Buying a bike based just on its motor

E-Bikes are attracting a completely different customer, one brought up on brand names from the household and automotive sectors. E-bike buyers on the continent are walking into stores asking for a Bosch bike or Brose bike, rather than a Specialized or a Trek – the sticker on the down tube carrying less currency than the one on the motor. But, in our view the motor is the least important aspect of choosing the best electric mountain bike. Much more important are geometry, suspension performance and overall handling. Most e-bike systems are perfectly good off-road, all delivering enough power, torque and range to satisfy most riders. The bikes that really impress us when we ride them are the ones that have got the fundamentals right; a bad bike doesn’t become a good bike just because it has a great motor bolted to it.

In this brave new world of motors and batteries, watts and amps, which of the three main suppliers in the e-mtb market is the ultimate super power? We pitted the Brose, Bosch and a couple of Shimano motors against each other…

Power

This is an easy win for the Brose Drive S-Mag. On paper it produces up to 90Nm of torque and supports your effort by up to 410 per cent. In the saddle that power is equally impressive, even when you’re revving the cranks, and the torque really packs a punch when accelerating and tackling steep technical climbs.

Next, and not far behind, is the new Bosch Performance Line CX. It can’t quite match the Brose for either power or support (340 per cent and 85Nm) but in most situations it feels strong as an ox with stacks of power to lean on.

Lagging a little behind is the Shimano STEPS E8000. It lacks a bit of torque compared to the competition (70Nm) and you’ll notice that if you’re riding with people equipped with Bosch or Brose. In isolation, it’s not normally an issue, unless you weigh a lot or like drag races and seeking out the gnarliest climbing challenges around.

However the Shimano EP8 motor, on paper at least, brings the torque figure up to 85Nm and makes that power a lot more accessible to the rider through brand new software. The new Trail mode lets you tap into all that power and tune the characteristics to your heart’s content with the new e-Tube app. So far we’ve been impressed with the new motor’s light weight, low noise, compact size and improved engagement, but it doesn’t quite feel as powerful as its two main rivals.

Response

Tying for top spot here are Bosch and Brose. Need to get going again on a climb or out of a corner and both of these motors deliver a near instantaneous reaction. The Shimano system is by no means dim-witted, but it’s not quite as responsive as the two German systems.

Battery capacity

The bigger the battery, the further the range; it’s as simple as that. And in case you weren’t sure, more range equals more money and more weight. At the moment there’s no clear winner here.

For Brose system, Specialized offers a 700Wh battery on most models, but you can also buy a 500Wh battery as a spare that will fit in the same space if you want to save some weight. Bosch’s revamped Performance Line CX has several battery options, from the widely-used 625Wh to larger 750Wh battery option that provides a decent range in a single internal unit that doesn’t impede the handling of the bike. Now Shimano has also updated its battery line-up to include a high capacity 630Wh unit, but we’ve found that the range is poor with the Shimano batteries compared to similar capacity systems from other brands. Luckily Shimano allows bike brands to spec batteries from third party vendors (although read the warranty small print) and these have proven significantly more efficient in our experience. Canyon now offers its new Spectral:ON with a huge 900Wh battery that lets you ride around in Boost mode all day without a care in the world. And better still, the bike is still incredibly agile and fin to ride.

Control and integration

Specialized’s Brose switch control unit is our current favourite, as it’s neatly engineered to be discreet but easily accessible, and you can run a small remote on the bars, or rely solely on two top tube mounted buttons. Additionally, Specialized’s Mission Control smartphone app lets you tune the motor, check range and troubleshoot problems quickly and simply.

Shimano hooks up a sleek and minimal push-button E7000 remote to a small display unit tucked behind the handlebars. It’s easy to change modes, doesn’t compromise your dropper post remote position and lets you see just enough information to help you manage battery life.

Bosch has lagged behind the other two in the display/control unit department for serious mountain biking, but it’s newly released options include a discreet display/control unit that can be integrated into the top tube and run without a secondary remote on the handlebar – perfect for the high performance e-mountain biker.

Noise

Another win for the Brose unit here, as its belt-drive internals mutes the whine. Although the new Shimano EP8 motor is similarly quiet. Bosch is next in line in this department, but it’s still not much better than the vocal Shimano STEPS E8000.

Reliability

Now the Bosch Performance Line CX was launched in 2020 and Bosch felt confident enough in its reliability a year later to unlock an extra 10Nm of power from the unit. From our experience it’s also been reliable if maintained and looked after properly. Shimano’s E8000 has also proved mostly reliable, although it does depend to a degree on the specifics of the electrics. Some bikes may be more prone to water ingress than others, and this can cause issues. Since the well-publicised failures of the Brose S-Mag fitted to Specialized Turbo Levo and Kenevo models, upgrades to the belt and changes to the software seem to have largely fixed the reliability issues. We’ve been running one on the new Turbo Levo for over a year now and over 1,000 miles without serious issue. Only a couple of times the motor has registered an error – quickly fixed by switching off and on again – but it does feel like it’s not quite as strong as it was when brand new. As with all motors and wiring, being careful around water is key, so not using a jet wash or excessive amounts of water is recommended, as is drying the bike immediately after cleaning.

What is the best motor?

With the e-bike market in a constant state of flux, today’s market leader can fall behind at the flick of a switch. At the moment, for pure ride experience thanks to its rapid response, intelligent eMTB mode, powerful motor and addictive overrun feature that lets you power over steps and ledges on climbs, we’d say the Bosch Performance Line CX edges it. But, the displays and control units are bulky and awkward to use.

On the other hand the new Shimano EP8 is lightweight, smooth, ultra quiet and boasts one of the best rider interfaces on the market. However it feels a tiny bit down on power compared to the Bosch, and lacks the same level of overrun, so isn’t quite such a weapon on technical climbs. While the Brose S-Mag is seriously powerful and, when fitted to Specialized’s e-bikes, comes with the best rider interface and battery range on the market, and now the reliability issues seem fixed, it’s a great package.

Other e-bike systems:

Fazua Evation Ride 60

The Fazua Ride 60 motor arrived back in April this year with very little fanfare and even fewer brands promising to use the system. None, in fact, unless you’re counting commuter bikes. Which we’re not. The spec looked like a great improvement on the old Fazua drive unit, and of course bike builders working in the background to get their bikes ready knew that. And now we have a bunch of them putting battery to bike.

Fazua’s original USP was that you could remove the battery and motor and ride the host bike with pedal-power alone, dropping its weight and taking advantage of the largely resistance-free motor. Ride 60 lets you remove the battery again, and now the power has crept up to 60Nm torque while max output has jumped up to 450W from 350W. Not bad for a drive unit that weighs 1.96kg.

More power’s no good without the juice to back it up though, and thoughtfully Fazua has increased it to 430Wh from 252Wh in the old version. You can top that up too with a range extender and 200Wh of charge.

TQ and the Trek Fuel EXe

Most of us had never heard of TQ until the launch of the Trek Fuel EXe. It’s a German brand that makes motors and components for robots, satellites, space stations and mars rovers. Literally space-age stuff. Now it’s partnered with Trek and introduced us to a new motor that’s impressively light, powerful and quiet. Best of all, we’ve had a go on the new bike, turn to page xx and you can check out our first ride impressions.

What’s different about the new TQ-HPR50 motor isn’t exactly the weight and the size of the unit, although it is indeed very light, coming in at 1,850g. The Specialized SL motor weighs around the same at 1950g. No, the new bit is the amount of power it generates and the lack of noise it makes while it’s doing so – 50 Nm of torque and 300W peak power are the seriously impressive headline figures. Suddenly the SL’s 35Nm and 240W start to sound a little underwhelming.

The TQ-HPR50 also claims to be extremely quiet and reliable, thanks to its minimal use of parts and lower RPM than a conventional e-bike motor. There are no cog wheels inside either, meaning less friction, which is great for the engine’s power and yours. There’s less noise because of that too, less wear and less chance of it failing, TQ says.

More power begets bigger batteries, but Trek says it’s backed away from the massive down tube arms race here, instead opting for a 360Wh removable power pack, and an optional 160Wh range extender to slot into your bottle cage. At 1,830g, it’s really lightweight too, and the Fuel EXe benefits from its slim profile with an equally skinny downtube.

For two years, the Specialized Kenevo SL was the poster boy for e-bike riders who didn’t like e-bikes. If any bike was going to convert the sceptical, it was little Ken. Not anymore.

Forestal/Bafang Eondrive

A young upstart, unhindered by the baggage of an established industry, fleet footed and agile, founded by an ambitious tech entrepreneur and with galactic-size plans for the future, Forestal is in many ways the Tesla of mountain biking.

Imbued with talent from Mondraker and Commencal, this high end start up now offers a range of three different lightweight e-bikes with more on the horizon. At one end of the scale is the 150mm travel Forestal Cyon – a 29er trail bike and the lynchpin of the range – then there’s the Siryon enduro bike with 170mm travel, and finally the Hydra which gets spiced up with a dual crown fork up front.

Forestal worked closely with Chinese manufacturer Bafang to create the bespoke EonDrive motor, designing the bike, motor, battery and control unit as a cohesive system rather than a series of off-the-shelf components bolted to a frame. Vital stats for the motor are a weight of 1.95kg and a torque output of 60Nm, 400w peak power and it’s hooked up to a 360Wh internal battery with the option to attach a 250Wh range extender. It’s a compact, narrow motor that keeps the weight low and the handling dynamic, but there’s enough grunt at low revs to get you up some really challenging technical climbs.

It doesn’t stop there. Forestal also integrates a sophisticated colour touch screen into the top tube, giving GPS mapping and data on power, range and even airtime. Plus, the full carbon frames can be custom painted in a stunning array of colours, any of which would look at home on a supercar.

In the next few years Forestal is looking to bring the manufacture of its carbon frames in-house, to Andorra, meaning it will no longer be reliant on factories in Asia. And the new construction technique it’s developing will also allow the recycling of any waste material, and even frames themselves once they’ve reached the end of their life, into useful parts. Look out for a first ride on the Cyon in the next issue, and Silverfish is due to receive its first batch of bikes in the UK any day now.

 

Panasonic GXO

The newest kid on the block, electronics experts Panasonic have a freshly introduced eMTB motor, the GXO. Currently only available in the US (but soon to be over here) this unit claims to be the one of lightest and potentially the most powerful in terms of out and out torque. With a whopping 90Nm available, this should translate into a punchy ride with bags of low end grunt. Panasonic has been a long time supplier of battery cells for existing motor brands but now has two internal batteries options of its own design. Choose between the lightweight 288Wh version for fast and light rides on home trails or a larger 432Wh battery for longer forays. The large display is centred over the stem for easy visibility and is connected to a multi-function button unit that sits neatly next to the left hand grip.

Giant Syncdrive Pro/Sport

Giant has completely adapted Yamaha’s existing PW-X motor system to provide it with exactly the right performance features it required. It’s a little more stripped out to produce a motor weight of 3.1kg, that’s pretty competitive currently. Its party trick is its ability to produce up to a leg snapping 80Nm of torque and up to 360 percent of additional assistance. In the top three power modes the Syncdrive Pro can support a cadence of up to 120rpm (110rpm in the lowest two) without any loss of power.

Like Shimano’s STEPS it uses a standard crank/chainring combination to maintain traditional q-factors and pedal feel. It also uses a responsive ratchet/bottom bracket interface to provide almost instantaneous drive.

Giant’s RideControl Evo headunit sits above the stem and has a large display that’s easy to read. It gives battery life as a percentage so you can accurately work out how much power is left and you can also divert power to charge your phone via the in-built USB port.

Giant list three specific battery capacities but it’s only the bigger 400 and 500Wh Panasonic produced batteries that are used for eMTBs. Giant’s fast charger ensures that even the bigger capacity systems can be fully charged in around three hours.