Motor matters

Brose, Bosch, Shimano… which has more power, which packs more battery punch, which is more reliable? Our quick guide to e-bike motors has the answers.

>>> Best electric mountain bikes in 2019

The government has just announced the removal of the £1,000 limit for its tax-free cycle to work scheme, bringing e-bikes into the equation for the first time. Is this the tipping point that makes e-bikes the norm, rather than the minority, on Britain’s trails?

With the potential to save around 30 per cent off the price of a new bike, the UK could be poised to see a similar growth spurt in new e-bike sales to that witnessed across the channel in countries such as Germany, Austria and Switzerland.

And it’s here that 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.

So, 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?


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 75Nm) 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.

Bosch Performance Line CX


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.

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 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, but all of them are bulky and overcomplicated compared to the competition.


Another clear win for the Brose unit here, as its belt-drive internals mutes the whine. Bosch is probably runner-up in this department, but it’s still not much better than the vocal Shimano STEPS.

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Shimano STEPS 8000


Tough one to call this. We’ve had problems with both Shimano and Brose-equipped bikes (mostly due to water ingress) while the Bosch Performance Line CX is too new to judge. Bosch and Shimano both offer standalone backup in the UK through Bosch UK and Madison. That said, with Specialized selling the bulk of Brose-equipped bikes over here, support shouldn’t be a problem either.

Brose e-bike motor on Specialized Turbo Levo


With the e-bike market in a constant state of flux, today’s market leader can fall behind at the flick of a switch. But if we were to nail our colours to the mast right now, we’d say Brose Drive S-Mag has the edge in the motor wars, with the new Bosch Performance Line CX a close runner-up and Shimano’s STEPS E8000 a little further behind.