Power games

It may sound obvious but until you’ve ridden an e-bike you may not appreciate how e-bike motors vary and what it means for your riding experience.

>>> Best electric mountain bikes in 2019

Shimano STEPS

Vying for top position amongst eMTB motor units, Shimano’s STEPS system has gained massively in popularity amongst manufacturers thanks to a few key features. It boasts the lightest overall weight amongst the main contenders at just 2.8kg. It also takes up less room than many of the other motors, with a neat and compact design that integrates subtly within the frame and further enables the use of shorter chainstays. Thanks to this compact size it also benefits from one of the narrowest q-factors to give the most natural pedalling ‘feel’.

Whilst it only offers 70Nm of torque (lower than most of its rivals), STEPS provides a powerful and seamless level of support regardless of pedalling cadence. It also applies and increases this power in a very smooth and progressive way throughout the settings, with no noticeable ‘steps’ in power provision. When pedalling over the 25kph threshold it’s also good to know there isn’t a wall of friction to overcome to limit the performance.

Five modes of power level are available including the smart Trail mode that automatically adapts power levels dependent upon terrain.

The STEPS display is one of the most user friendly and intuitive units out thanks to neat visual and colour representations of the differing power settings. It also sits safely out of the way behind the handlebar, taking up little space and protecting it from crashes and when you need to flip the bike upside down.

As long standing MTB component providers, Shimano has nailed the crank interface. A shorter 165mm XT crank runs on a standard Hollowtech II bottom bracket. This now has provision to run a direct mount chainring compatible with anything up to 12 speed drivetrains.

Shimano has a single, externally mounted 504Wh battery option, however several manufacturers are using compatible, proprietary internal batteries.

Bosch Performance Line CX

Bosch has been driving the eBike market for several years and one look at its market share shows how popular the brand is. The Performance Line CX represents the pinnacle of its eMTB line and has the best of Bosch’s technical features built in. It provides up to 75Nm of torque and this is applied through a wide range of pedalling cadences all the way up to a thigh burning 120rpm. The Performance Line CX offers a little more kick on startup than other motors with an impressive surge of power.

The critical difference between the Bosch unit and other motors is a reliance on a mini drive ring and internal gearing rather than a standard chainring operation. This keeps the chain out of the way but the added internal workings add up to a hefty 4kg weight and a boxier size. This size does impact on crank width and limits chainstays length options.

Four power modes are used to eke out the power with just the top two, Turbo and the smart eMTB, providing the full 75Nm of power. eMTB adjusts the assistance from 120 to 300 percent, dependent on cadence and pedal pressure. The walk assist has also been boosted for 2019 to provide more assistance over hike-a-bike sections.

There are now four display options from Bosch including the new for 2019 Kiox headunit. Similar to Shimano’s display, this now uses changing colours to quickly determine which mode you are currently in. It’s also specifically designed for MTB use with a scratch resistant screen, tactile buttons and steerer tube mount.

Bosch offer a range of battery options to suit power needs and frame design, including the popular 500Wh internal PowerTube.

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

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.

Brose Drive S Mag

The original Brose Drive found traction as the motor used in all of Specialized’s Turbo Levo models but was a bit of a brute. The latest Drive S has been put on a diet, both in physical size and mass, whilst managing to shoehorn even more power into the unit. By incorporating a magnesium housing rather than the more traditional aluminium, Brose has dropped over half a kilo in weight and made the unit 15% smaller.

The Drive S Mag also boasts some impressive performance figures too. How does 410% of electronic assist (it will add four times the effort you apply) and a maximum torque of 90Nm sound? It also has a new Flex Power Mode, which allows assistance at much higher pedalling cadences than ever before. Three display options are available including a larger information-rich unit, a smaller vitals-only display and a button-only option.