Your guide to all the most popular mid-mounted e-bike motors on the market, from Bosch to Brose to Yamaha, Fazua and Shimano.

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Brose, Bosch, Shimano, Fazua, Panasonic, Giant ebike systems… which has more power, which has more battery punch, which is more reliable? Our guide to e-bike motors has the answers.

E-Bike motor torque power at a glance

  • Brose Drive S-Mag: 90Nm
  • Panasonic GXO: 90Nm
  • Bosch Performance Line CX: 85Nm
  • 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

Read more: Best electric mountain bikes – join the riding revolution!

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.

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…

Shimano EP8 motor lacks grunt compared to alternatives

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.

Bosch Performance Line CX

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 systems, Rotwild offers 750Wh and Specialized 700Wh on their top of the range models. However, Focus’s piggy-back TEC pack system (standard on the Focus Jam2 and Sam2) plugs into the Shimano motor and gives you two 380Wh batteries, equalling 760Wh, and this is now included in the price of the bike. Bosch’s revamped Performance Line CX has a 625Wh 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. Don’t need the extra range? Shimano also offers 504Wh versions of its internal and externally mounted power packs.

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 EP8

Shimano’s new EP8 motor

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 lags behind the other two in the display/control unit department for serious mountain biking, with options that seem designed mainly for leisure riders. There are several options in the line-up, including the new Kiox colour display and Purion integrated display/control unit, but all of them are bulky and overcomplicated compared to the competition.

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.

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Shimano STEPS 8000

Reliability

Now the Bosch Performance Line CX is a year old, Bosch obviously feel confident enough in its reliability 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 dgeree on the specifics of the electrics. Some bikes may be more prone to water ingress than others, and this can cause issues. At the moment, the most failures we’ve seen have come from the Brose S-Mag fitted to Specialized Levo and Kenevo models. This has been a mix of water ingress causing issues with the electrics and connections, and problems with the belt drive failing within the motor itself. While Specialized has quickly moved to address this with enhanced warranties on its e-bikes, that won’t help if your motor stops working miles from home.

Brose e-bike motor on Specialized Turbo Levo

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, the historical failure rate means it has dropped down our list of favourite motors.

Read more great e-bike content on our E-Bike live hub-page

Other e-bike systems:

Fazua Evation

Coming in distinctly left of field, German brand Fazua produces a completely different style of motor and battery system. Based around a completely modular and removable system, for many this approach represents the potential future for e-bike design. Called the Evation, this revolutionary system weighs just 4.7kg for the whole kit; that’s battery, motor, drive unit and all associated electronics! Compare that to the main systems where just the drive unit weighs over 3 kilos and you have the possibility for building a very light eMTB. Granted the 1.3kg battery only has a 250Wh capacity but with such a paltry weight you could stuff another in a pack without really noticing it. It also puts out a lower level of assistance than many of the larger units but turn the power off and it’s obvious that the Evation still provides a large degree of assistance. The most interesting aspect though is the removability factor. Promising zero friction with everything removed you can now potentially have one bike to do it all.

Panasonic GXO

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.