Electric bikes are an evolutionary leap since the invention of the humble and evergreen bicycle. With an extensive range available at substantially different price points, it gives consumers much to think about. To help you on your journey we have put together a comprehensive guide on what to consider when buying an electric bike.
Electric bikes 4 step buying guide
What is your purpose?
Consider how you will mainly use an electric bike (e.g. everyday commuting, off roading, touring) to make your decision accordingly. Bikes are not all purpose utilities and although most of us use them in that way, it often makes for less than ideal experiences. Therefore, deciding on the main use for your bike significantly helps to inform your decisions about the components and performance.
Consider quality over price.
Its important to realise that electric bikes are not toys. In order to use it chiefly as your mode of transport, you undoubtedly need it to be reliable. The quality of the bicycle itself irrespective of the drive system is highly important. An initially cheap purchase may subsequently end up costing more on maintenance in the long run.
Availability of spare parts and after sales service
When buying an electric bike be sure to ask about spare part availability and especially about after sales services. Like other electrical devices, in time there’s a chance your electric bike might break down. Every bike is built differently making spare parts difficult to source and small importers often have no knowledge of how to repair their own bikes.
Try all the different bike types and go with your instinct.
Notwithstanding what you have been told about one type of drive system compared to another, they each have their benefits as well as limitations. At the end of the day it comes down to what you feel most comfortable riding!
Details that matter
Electric Bike Batteries
How far do they go?
The capacity of the battery is measured in Watt hours (Wh), or Ampere hours (Ah). The speed and the load of the trip is also a significant factor on the mileage of a charge. The weight of rider + vehicle can vary by up to 100% between users while the speed you choose to ride vs another rider can easily affect the energy requirement by 300% thanks to aerodynamics. Finally, there’s two energy sources, the battery and the human, with human power generally under measured. Generally most e-bikes claim to have a charge of minimum 30 kms on 10ah battery up to 100 kms with larger 28ah battery.
The best advice we can give is always look at the battery capacity on a given model and get the bigger battery available – nobody complains about having a battery with too much range. Battery capacity will decrease over time so start day 1 with spare reserves. Figure out how far you want to go on a charge and if the retailer cannot recommend or guarantee a battery that will go the distance, request a long test ride so that you can find out for yourself. If there isn’t a battery available for the model you want to cover the distance you need, then it’s not a smart buy.
How long do they take to charge?
When they are fully drained, Li+ batteries generally take between 3 to 6 hours until they become fully recharged. Based on math, charging a 10Ah battery with a 1-amp charger will take 10 hours…or 2 hours with a 5-amp charger. Most chargers are specced between 2 and 5-amps.
Center or rear mounted battery?
Weight balance is important for rider comfort and usability and must be kept low and centered on the e-bike. Rear mounted batteries in addition with a rear wheel drive and/or weighted panniers could make the bike unbalanced and difficult to ride.
Electric Bike Drive System
There is a lot of talk about the different drive systems and which is “better”. Again, it comes back to your purpose, does it suit the needs of your bike trip? Are there spare parts available? What is the after sales service like and most importantly what you feel comfortable riding. If you don’t feel confident about any of the above, consider trying different bikes.
Front wheel drive
- This is very low maintenance as it shares the load on the bike between the front wheel (motor power) and rear wheel (human power and rider weight).
- It also separates the motor from the rest of the bicycle parts, making it easier to service and spares are more aligned with normal bike parts.
- Allows any type of gearing in the rear wheel, such as internal hub gears for little or no maintenance. No matter where the battery goes, you’ll end up with a well balanced and very stable bike.
- Best suited for commuters, touring (depending on your terrain) and rail trails.
- Not recommended for mountain biking or on gravel, loose dirt off road trails
Rear wheel drive:
- Both front hub or rear hub motor have similar performance as it has similar design constraints, both are very efficient in propelling the bicycle without a drive chain (direct to the spokes).
- Rear hubs mean a light and manoeuvrable front end. All your weight is on the motor, giving it maximum traction even in adverse conditions.
- As your rear wheel and spokes take higher stress with your weight, pedal power, the motor’s power, the motor’s weight and even the motor’s dimensions, it makes for a more difficult wheel build than a conventional wheel. An electric bicycle with rear hub motors might break spokes more regularly, so make sure the ebike you’re buying has a high quality wheel build.
- Best suited for off road riding on steeper / loose tracks and on bikes with a high standard of manufacturing and components.
- Less than ideal for every day commuters who want a low maintenance bicycle.
- Allows both wheels to be ‘normal’ bicycle wheels, giving all the available options of quick release, internal hub gears etc. Front forks can be interchanged at any time and both the front and rear end are kept light. Centre of gravity is low and the whole e-bike is usually lighter too. The drive is via the rear wheel, so traction is not an issue. Rear wheel spokes are not stressed as much as on a rear hub motor setup. Motor is geared, so going slow and steady up very steep hills is achievable but it also means it you are required to do more work.
- More complicated system, so motors are usually more expensive and the proliferation of sensors in the bike adds to possible failure modes. The drive-chain is under increased stress (human + motor power through the chain), requiring more regular maintenance and parts replacement.
- Best suits mountain bike riders or people who want a bike that feels more like a normal bike.
- Less suitable for hill climbers or riders who can’t rely on their body to do most of the work. Riders where budget for maintaining and replacing chains, cassettes, rear hubs etc is limited.
A person of 70 – 90 kgs only requires about 150 – 180 watts to move at a speed of 24 km/h on level roads. Therefore a motor of 180 to 250 watts should be more than sufficient when combined with our own effort. With a 300 watt motor you should have no worries at all tackling hills. A simple pedal assist should get you up most grades, making your job even easier than most conventional 21 gear bicycles.
Not all equally rated motor (e.g. 300W) perform the same. A good electric bicycle depends on both the motor and the controller working in harmony. Acceleration, torque, maximum output and assistance factor are the real judges of what a good electric bicycle should be. It is always recommend to try several bikes before making a decision.
As electric bike owners tend to use their bicycles more, having brakes that perform well in a range of road and weather conditions is essential. Quality brakes offer consistently high performance with minimal maintenance
Since electric bikes also tend to be heavier and faster bikes while carrying more than just the rider, hydraulic disc brakes are better in almost every way for electric bicycles.
Electric Bike Warranty
There are many manufacturers and importers of electric bikes. As complex transportation machines subject to adverse conditions, it is equally important to choose from a reputable manufacturer, a reliable importer and obviously a local bicycle shop that is knowledgeable and can provide after sales service.
Most electric bikes will have a 1-2 year warranty on components and battery and a extended warranty on the frame. Every bike is built differently making spare parts difficult to source with small importers often having no knowledge of how to repair their own bikes. With this mind, be clear about the warranty terms and where the seller recommends getting your bike serviced should anything go wrong.
Low Powered Vehicle Law in NZ
By and large, most electric bikes are manufactured to European or American regulations, putting them at 25km/h to 32 km/h respectively. NZ regulations caps the motor rating to 300W, exceeding this conversely puts the vehicle into a scooter / motorbike category, requiring type approval and a driver’s license. Read directly from the NZTA website here.