Watt eBike

5 min read

Arguably the most significant (almost) new thing on two wheels is the electric bike. In the short time they’ve been around, the technology has progressed at an eye watering rate. Only two years ago Steve (Ground Effect’s resident bike fondler) made the fiscally rational decision to retro fit a Bafung mid drive to an old Santa Cruz mountain bike that had been retired from active service. Affectionately known as Frankie (as in Frankenstein), it's a fabulous off-road commuter. The task suited Steve’s engineering temperament and his patience to massage the wrinkles during the conversion process. However, the project is not one he would entertain in the current climate - with so many seductively well-resolved designs on offer from almost all the leading bike brands.

The Frankenstein experiment.

It’s not in any way definitive, but UK publisher Bike Radar has recently complied a useful summary of the broad eBike categories, examples of bikes they like, and their pros and cons.

Fit for Purpose

In an over simplified view of the world, eBike designs typically sit on a spectrum with features that suit commuting at one end and mountain biking at the other - with a generous overlap in the centre that covers rail and cycle trails.

So, if you’re in the market, start with obvious introspective question “How am I likely to use this bike?” This will provide some clarity when evaluating the potentially confusing price-features-attributes minefield.

Be mindful that while current designs and battery technology are well-resolved, invariably eBikes will continue to evolve and improve - getting better and cheaper each year. There's a wealth of information to trawl through at E-Mountainbike Magazine.


Most commercially available eBikes have a 250-300 watt motor, are pedal assisted (go when you pedal, cut out when you stop pedalling or reach 32 kph), have aesthetically-pleasing integrated batteries and clever proprietary handlebar mounted controllers to manage power and distance.

eMtbs generally have a mid-drive motor around the bottom bracket to provide solid torque through a variety of terrains. The more sophisticated controllers will read your mind and deliver power at exactly the right point in your pedal stroke when navigating technical obstacles.

eCommuters may also have a mid-drive, although the less expensive models tend to use a hub motor in the front or rear wheel. They work just fine but need to be optimised for either flat riding or hilly stuff.


eBikes have transformed commuting, emancipating riders with a non-sweaty cruise to work at an elegant 32 kph - while retaining the traditional bicycle benefits of reduced road congestion, a hit of exercise and absence of parking frustration.

The standard front triangle-type conveyance with maximum versatility is the default choice for many. However if your steed is intended purely for town and around then other frame configurations may deliver more benefits.

Ground Effect recently acquired a bright orange Tern GSD cargo bike, affectionately nicknamed ‘Fanta’.

Scott and Fanta factory-bound with a load of zips.

The ’sit up and beg’ position with increased vision is easy to navigate amongst traffic and riding with a straight back is very relaxing. The motor compensates for the non-aerodynamic upright stance and reduced pedal power. It has significant carrying capacity for stuff and/or little people. Swinging your leg across the low top tube to mount and dismount completes the bike’s urban sensibilities.

Skill Me

eBikes have opened up rail and cycle trail trips to a new breed of adventurers.
The less-fit can tackle a long day without blowing their foo-foo valve. And less experienced family members can travel at the same pace as the rest of the crew. A word of caution…compared to their non-powered cousins, eBikes are heavier and travel faster. If your two wheeled skills are a little rusty then invest some time practising before you head out - especially braking and cornering on a shingle surface. Also master smooth gear changing. The motor generates a lot of torque, exacerbating drive chain wear ’n’ tear. Clunky shifting can cause breakages.

Flying High

Taking your bike on holiday to exotic locations is a joy. But airline restrictions make eTouring a little tricky. Expensive eBikes tip the scales at around 20kg - most nearer 25-30kg so your eBike alone is nipping at the airline’s baggage allowance and the 32kg maximum weight for any single piece. More problematical, lithium-ion batteries can’t be checked in or carried on as cabin baggage due to fears of spontaneous combustion. You’ll need to buy or rent a battery at your destination. Rental is not that common yet. Hiring an entire eBike may be a more pragmatic solution.

Passing Wind

eBikes are fast. On the flat you’ll easily hit the 32kph max and you’ll climb uphill at 15-20kph with minimal effort and sweat. The (unexpected) consequence of this is that windproof layers are really important to keep you warm. A waterproof or water resistant jacket and pants is the foundation. Also consider windproof gloves, a beanie under your helmet, and windproof socks or over-shoes to protect your extremities.


Off-road eMtbs are arguably the most sophisticated, most expensive and fastest developing category. In Europe, and increasingly in other markets, they outsell their non-powered siblings in most shops. Some points to consider:

  • Uplift The most obvious benefit of eMtbing is uplift - largely negating the need for chairlifts or shuttles as you effortlessness truck uphill at 20kph.
  • Downtime And the obvious upside is more laps and more gravity-assisted joy than normal.
  • Further, Faster In the modern ‘resource rich-time poor’ society an eMtb lets you score more biking and cover greater distances in a given time. If you’ve only got two hours after work - then you get more bang for your buck than is otherwise possible.
  • Jane Fonda It’s still a workout. If you’re a Type A personality then rather than making your ride less energetic, you’ll work, sweat and blow just as hard but go further and faster.
  • Ride like Danny MacAskill Extra power lets you successfully tackle tricky (often steeper) technical track.
  • Gimme a Brake An eMtb is heavier, requires more stopping power and handles differently on descent.

Mike Cowlin on Lithium at the Coppermine. Photo Digby Shaw 

Power Management

Batteries run out of juice. Recharging is often not an option. So, on longer trips you’ll probably want to carry a spare battery and conserve power by selecting economy mode rather than turbo.

Clean and Jerk

At around 25kg eBikes are too heavy to sensibly hoist onto the roof of your car. And they will almost certainly exceed the weight limit to travel up there safely. A standard tow ball bikerack will also struggle - especially if you’re transporting two or more eBikes. You are likely to end up with a solid 2” hitch mount rack from the likes of Thule or Yakima to cart your eBikes around.

Brave New World

A final caution when belting around town on your eBike. Car drivers are not yet adjusted to bicycles approaching at high speeds and will often pull out in front of you in the mistaken belief they have plenty of time before you come thundering through. Always bring your A-Game when travelling amongst traffic.

May the force be with you.



6 Responses

Ian Selwood
Ian Selwood

May 24, 2019

Starting to see a few e-bikes on the Coast now. Can be pretty disheartening tackling uphill sections of route, to be passed by an ‘old fart’ on an upright bicycle dressed in an old suit and plimsol’s.. Although I find that 32km upper limit comes into play to make up ground on them on the flatter sections!

Paul de Spa
Paul de Spa

May 23, 2019

As an addition to the Brave New World section and based on my 4yr experiences e-commuting… “Bring your A-game” – yes definitely: don’t let your mind wander for even a second when e-biking in traffic.
Also, fit a really powerful front light (my Ezee Torque came with a 1000 lumen light), and ride with it on at all times – you will look like a cross between a bike and a motorbike, which you are!
And, use the road space (again, think like a motorcyclist) – at 35km/h you can ride out into the traffic stream more easily and safely, and it is often a better place to ride and be seen than on the shoulder (although there are times when you’ll have to ease up and ride as on a regular bike too).

Helen Wenley
Helen Wenley

May 23, 2019

I have had my Gepida Ebike for just over a year and have ridden almost 5200kms so far. I call it my freedom machine. I belong to Ebike Social Riders Hawkes Bay group and we cycle together once a week and sometimes more. I own Ground Effect clothing, shorts, jacket, wet weather overpants and a vest. I am hoping that bicycle clothing companies will provide more jazzy clothing for us ebikers.

Barry Page
Barry Page

May 23, 2019

For Rod – the physics don’t work out. For that matter the mechanics don’t either, as regeneration and freewheeling motors don’t mix. https://electricbikesnz.com/2016/10/29/the-myth-of-free-energy/
Regarding wind protection – totally agree – one of my greatest annoyances commuting is noise across the ears/helmet straps etc. A ‘buff’ or similar across the ears works wonders.


May 22, 2019

How far off are bikes that will charge their batteries on the downhill sections?Why dont Bosch have a simple upgradde from 25 to the new 32kph bike?
Keep pedalling Rod

stuart gardyne
stuart gardyne

May 22, 2019

excellent succinct summary. Really useful as an as yet non eBiker. The Jane Fonda comment was a revelation. I had thought getting an eBike would be a slipperly slope towards diminished fitness. It probably is for commuting as the distance remains the same. But for off-road…

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