E-MTBing with pedal-assist
Almost all E-MTBs the big brands are bringing into Australia are pedal-assist. This means that the motor is actuated by your pedalling action, and the harder (or faster) you pedal, the more assistance the motor provides. With pedal-assist, it’s easy to cruise up the hill to your favourite descent as many times as you like. E-MTBing feels a lot like watching your favourite movie, but with all the ads on fast forward.
The amount of support your E-MTB delivers depends on the ride mode you’ve selected. Shimano’s STEPS E8000 system, for example, has three settings, Eco, Trail, and Boost. In the Eco setting you’ll still need to put in a bit of effort to crest that big hill, while in Boost setting you’ll nose-breathe all the way to the top (be careful, you’ll be using your battery power faster, too!).
Pedalling feels natural, but more powerful, like you’ve woken up with superpowers. Shimano’s STEPS system is designed around the specific needs of mountain bikers, so it the motor assist cuts in the second you begin pedalling, and cuts out as soon as you aren’t. If you’d prefer to descend without any assistance when you put in the odd pedal stroke between berms, it’s simple to turn assistance off with the bar-mounted Firebolt switch—which looks and feels just like a Di2 shifter.
What about fit?
In recent years, manufacturers have developed E-MTB-specific drive systems. These drive systems are optimised so that handling and fit aren’t compromised by the introduction of E-components. Shimano’s E8000 system, for example, integrates a compact motor into the bottom bracket. The motor placement gives an intuitive ride feel, responding instantly to pedal feedback, and its size means E-MTBs can be constructed with the same short chainstays and narrow Q factor as ordinary mountain bikes.
And the weight?
There’s no denying that E-MTBs are heftier than their analogue cousins. While the weight of E-MTB systems is coming down, the motor will add at least three kilograms, while the battery adds another two or three. Good manufacturers also build strong E-MTBs, so there’s often also a bit of extra weight in tougher wheels, frames, and suspension than might be the case on a similar bike without the electronic assistance. Good quality E-trail bikes will tip the scales at 20–24 kilograms—not too much to lift if you need to, but enough to change the bike’s handling.
Good E-MTB systems also come with a Walk mode, which provides a tiny bit of power to help manoeuvre the bike when you’re wheeling it to and from the car, or across the road, or maybe if you chicken out on a trail feature.
On the trail
E-assistance looks after the extra weight on the hills and flatter terrain, but what about downhill, through berms, over jumps and drop-offs? E-MTB handling is a bit different all-round. E-MTBs, apart from being heavier than analogue bikes, also often have slightly different geometry to accommodate batteries and motors.
While it’s true that more weight means more to push around in corners, recent developments in E-MTB drive systems are focusing on getting battery and motor weight as low as possible, as this can actually enhance ride feel relative to traditional mountain bikes. Some riders find they feel more stable on steep descents and in the air on E-MTBs thanks to the added stability. Think of the low weight acting like the keel of a ship, keeping the bike planted and stable, even when it’s getting thrown around.
Still wondering? Try an E-MTB for yourself
Shimano STEPS and dealers of all the big bike brands are holding demo days regularly throughout Australia in 2017/2018. You can find out more about upcoming Shimano STEPS events here.