The main e-bike motor manufacturers are Bosch, Shimano and Brose. The latter’s new S Mag system is seriously powerful, quiet, integrated and has one of the best rider interfaces around.
It can deliver up to 90Nm of power and support your efforts by up to 410 per cent. That’s plenty for climbing and powering up steep technical sections.
1. Brose S Mag
The Brose S Mag is an impressive motor. Designed to be light and powerful, it works well on our test bikes and should prove a solid choice for manufacturers looking for an ebike motor with plenty of power and a natural ride feel.
The magnesium housing keeps the motor super light, despite producing 90Nm of torque. The drive uses a belt drive with double sprag clutches to provide silent operation. Even in Eco mode, it offers a good amount of support for climbs and is upgradeable to Pro (with extra torque) for more climbing power.
This motor is paired with a 720Wh battery on our test bikes and can be used to build a very capable E-Trail bike. It’s not quite as powerful as the Shimano EP8 but doesn’t run out of steam at higher cadences either. Its power window has been tuned to feel very natural, although we’d like to see it offer a little more assistance at the very top end of the range.
The S Mag is easy to control from a minimal display unit on the handlebars or with a smartphone app, which lets you tune the motor and check your power usage. It’s also a solid performer, with no issues in our test rides.
2. Shimano EP8
Since introducing its original XT-level E8000 drive system four years ago, Shimano has leveraged its bike component prowess to pretty much dominate the world of performance off-road e-bikes. Their new EP8 motor is marginally lighter and smaller (300g, 10%) but still offers the same power as the old unit. This allows brands to more neatly integrate the motors into frame designs like Canyon’s Spectral:ON or Orbea Rise and, with its magnesium casting, heat sinks and polished logos, offers a more stylish look than Bosch systems too.
The EP8 is able to produce up to 85 Nm of torque, which puts it head-to-head with Bosch’s top-of-the-line mid-drive motors. Unlike the Bosch system, which tapers off assistance at high cadence and power outputs, the EP8 is designed to continue providing power even at higher levels of pedalling. This gives the motor a more natural feel on the trail but does mean it doesn’t have quite the same ‘Boost’ mode range as the Bosch system.
As with the previous EP3 motor, the EP8 has an Eco and a Boost mode. In Boost mode, the motor is capable of reaching its full peak output of 85 Nm. However, it also allows you to progressively ramp up the power, which is ideal for sporty riders or when you want to save battery power. As well as this, the EP8 features an updated display/control unit that can be tucked into the top tube and runs without a secondary remote on the bars, making it ideal for serious high-performance e-mountain bikes.
3. Bosch Performance Line CX
Bosch’s latest Performance Line CX motor offers a great mix of power and efficiency. Compared to the previous generation, it’s now even more efficient with better torque delivery. It also has the fastest processing speed of any ebike motor with 20x faster power management and no lag.
It’s still the most affordable power unit on the market and a very reasonable choice for riders who want to upgrade to an eMTB with an internal drive. It’s not quite as fast or powerful as the Shimano EP8, but it still feels very strong and offers 340 percent of pedal assistance and 85Nm of power in turbo mode.
Bosch has also updated their Smart System platform with a few exciting features. The new system uses smaller modular connectors to hook up the motor, display and remote. This allows for more intuitive operation and a range of exciting software features, like adjustable support levels.
The new motor is smaller and lighter than its predecessor. It’s also more efficient with a more consistent and responsive torque curve that matches your own pedaling cadence. It also has a class-leading power management system and noise optimized gearbox for minimal vibrations. The Purion display is clear and compact, making it easy to access all your ride information.
4. Shimano STEPS E8000
The Shimano STEPS E8000 is a powerful and light drive system that’s perfect for e-mountain bikes. It has a great power range, is easy to use and can be tailored for your riding style. It also has a cadence sensing motor, which means it only provides assistance when you’re actually pedalling. This helps the motor last longer and reduces noise, while delivering just the right amount of support for each of your strokes.
Another big benefit of the new EP8 is that it’s 15Nm more powerful than the previous generation, which makes a massive difference on steep ramps and technically demanding uphill sections. This extra power also allows the new motor to be more intuitive when navigating obstacles and can help to make your bike feel like a normal e-bike.
This new motor has the same mounting interface as its predecessor, which should make it easy for e-bike manufacturers to add to their frames and allow end-users to customise the settings. It can be paired with up to a 630Wh battery and produces 85Nm of torque.
Compared to Bosch’s Performance Line CX motor, it can’t quite match the Brose for power and range, but it comes close and still feels pretty natural to ride. Both systems can be easily customised via your bike’s display and app, so you can dial in the exact level of power and support that you need.
5. Giant RideControl Evo
Aside from battery size and capacity, the amount of power a motor provides is one of the most important factors in an ebike’s ride quality. Higher torque and watt figures usually equal a more powerful-feeling motor, helping riders ascend steeper climbs or keep pace with their group on the road.
Giant’s mid-drive motor, paired with their EnergyPak 500Wh battery, is a great choice for those who wish to enjoy the convenience of an ebike while preserving their health. Its SyncDrive Sport motor has enough power to reach 20mph, and the bike’s lightweight and efficient 1x drivetrain allows for a solid attack angle on fast descents.
However, the motor can feel a bit binary in its power delivery when spinning the rear wheel from a stop, and it lacks the ability to feed in power more gradually to control wheelspin on technical or steeper climbs. While this isn’t a big deal on flat terrain, it can become an issue when climbing up a steep or technical climb where the extra help would be most appreciated. As with the other mid-drive systems, the Giant RideControl Evo display can be customised using their respective smartphone apps for more precise mode customisation, ride planning and tracking.
6. Panasonic GXO
Panasonic is a massive electronics giant making a big splash in the US ebike market with their own mid drive motor system. Their new GX0 is the lightest and most powerful system available on the market.
It weighs in at just 2.95 kg and delivers an industry leading 90 Nm of torque making it a true powerhouse. It’s a great solution for riders who want to feel like they are riding a normal bike but still have the ability to push a lot of watts without feeling exhausted. The system will be available on Van Dessel’s national championship winning line of ebikes (captain shred) and also the new Passepartout gravel ebike which will race in the UCI sanctioned first ever eMountain bike world championship series.
The system will be available on Univega ebikes as well. They will offer both rear mounted and front mounted battery solutions. The rear mounted will allow the battery to be positioned closer to the frame which will create a more compact cockpit. The front mounted option will allow the battery to be positioned closer the cranks which is great for creating a more sporty feel to the bike.
For those looking to get the most out of their Panasonic ebike we recommend getting our badassBox 1.0 tuning kit for it. This will enable you to remove the speed limiter and double your ebike’s top speed.
7. Volt SpinTech
If you want a quiet, smooth and reliable motor then the Volt SpinTech could be the one for you. They use a Bafang rear hub motor paired with a battery and controller that they design themselves.
They say that this system makes their bikes more responsive and more natural to ride. We’ve had a chance to test this and the result is certainly true. This is a solid electric mountain bike that doesn’t feel like a cheat, and it’s also very reasonably priced.
The motor will give you a boost to the point where it meets the regulatory limit for ebikes (25km/h). It’s enough power for a good cruising speed that will have your mapping app wondering how fast you are going, but in the lower modes the motor feels more like a nice, smooth boost rather than a hard kick.
The battery is protected by a lock that you activate using the bespoke security tag provided. This isn’t a substitute for a full lock but it does make the bike more difficult to steal. They’ve also made the display screen on this model so that it can’t be viewed by a passer-by without activating the key.
