Going Pro

Two Wheel Assist!

Pirez Electric Bikes


Issue 9, March 2018

Changing the world, One electric bike at a time.

Electric bikes or “eBikes” are growing in popularity as more and more people realise the health, environmental and financial benefits (not to mention the sheer fun!) that they offer. So we caught up with Daniel Periera, the founder of Pirez Electric Bikes in Melbourne, Victoria (Australia) who builds eBikes and sells mid-drive motors and kits that can turn your standard treadlie into a custom-built speed machine.

How did you get into this business? What’s your background?

I have always loved riding bikes and been fascinated with electronics and energy storage. I got into this business almost by accident. I had just moved back home to Melbourne after living overseas for a few years and got a job in the CBD, it was a one-hour and 30-minute commute to work (driving, then catching a train). I was wasting three hours a day on commuting - that’s 15 hours a week! I thought to myself that there must be better way.

I lived 27km from the CBD and in my younger days I would cycle to and from work, however I was a little bit older now, my work hours were longer and there were no shower facilities at work. So unassisted cycling was out of the question.

I decided the best solution would be to purchase an electric bike. On a bicycle, traffic is not an issue and with an electric bike I wouldn’t have to arrive to work sweaty. And the commute is much quicker on an electric bike compared to a standard bicycle, public transport, or even a car in peak hour traffic. At the time however the only electric bikes available were either high-end bikes priced around $7,000 or the cheap, heavy and ugly step-through Chinese-made bikes with lead acid batteries. There was nothing in between.

So I decided the best solution would be to build my own electric bike with a mid-drive conversion kit. I already had a well spec’d bicycle that I liked, so it made sense to retrofit it. I purchased a kit and battery and went about building an electric bike, and it turned out great!

I was very proud of my new electric bike build and would ride it to visit friends and family, just so I could show off this new concept. My brother recommended that I build another electric bike and sell it, so that others could it experience it too. And that’s how the business started.

Commercial units are fun, but you have DIY-install options too. Do they fit onto any bike, or do you need a specific bike to start with?

Our mid-drive motors are designed to fit the vast majority of bikes, so you don’t need a specific bike. The motors slide onto the bottom bracket of a bike, and these bottom brackets can vary in size from 68mm to 120mm. If you’re bottom bracket is out of the ordinary we have spacers and brackets that can be customised to fit. We love the challenge of custom builds and will always be able to find a solution for you.

What sort of technical level do you need for a DIY model?

You don’t need much technical knowledge to install one of our kits and battery onto a bike. You just need to be a little mechanically minded. With every sale we send out an email with instructional videos and we provide a lot of support along the way. If you’re not sure about something just give us a call – we’re here to help! Sometimes there will be issues that pop up with a custom build, but figuring out the solution is all part of the fun.

We regularly get customers who opt to DIY but just can’t get the bike looking as good as when it’s professionally done by us (because we do it every day), and they’ll end up bringing their bike in to us for some finishing touches.

For someone who hasn’t really seen an electric bike, can you explain the mechanics of how the motor provides propulsion (e.g., how it interfaces to the bike’s drivetrain)?

With electric bikes there are two types of motors: hub and mid-drive. The hub motor is connected to the wheel of the bike. The mid-drive motor is attached to the crankset of the bike. We only sell mid-drive motors as we find they’re superior to the hub.

The mid-drive motor turns the chainring/sprocket, similar to as if you were riding a non-electric bike, powering it along with your legs. This has benefits over the hub motor as the mid-drive motor uses the bike’s gears as a transmission; so the motor can run at the optimum RPM range.

Other benefits of the mid-drive motors include having the weight of the motor at the centre of gravity low on the bike. This makes for a better riding experience compared to the hub system, which has the weight on the wheel. That system is less efficient as the weight of the motor needs to be rotated with the wheel, making it harder to turn. In addition, because of the extra weight on the wheel, hub motors are more prone to buckles and flat tyres. Getting a flat tyre is no fun at the best of times, and getting a flat tyre with a hub motor is even worse!

We also recommend purchasing a gear sensor, which is designed to cut out the motor when you change gears. This is to stop damage to the bike’s drivetrain, and so you don’t hear that horrible crunching sound when changing gears.

What’s an eBike like to ride? Are they noisy?

One of the great things about our mid-drive conversion kits and electric bikes is that they’re absolutely silent. Riding past other cyclists they wouldn’t even know you have a motor. Similarly, riding at night, you don’t have to worry about waking up the neighbours, and when trail riding you don’t have to worry about scaring off the wild life.

Do you ride “with” the motor and it simply reduces the load, or can you let it do all the work like an electric motorbike?

It’s up to you. With our systems you can pedal a little and have the motor do most of the work, or you can pedal a lot and have the motor do just a little of the work. Or don’t pedal at all and have the motor do all the work, just like a motorbike! Or any combination of the above.

What sort of range/time/speed can you get from a charge?

That depends on the battery and motor setup you want and how you ride it. For example, on my bike I have our most powerful motor which is the 48v1000w and a 20ah battery. With zero pedalling and the motor doing all the work I can get 73km of range. If I pedal and help the motor I can get 120km of range or more.

One of our customers Matt Bishop, wrote an excellent article about touring on his electric bike. After riding 100km he had only used a 1/3 of one of his batteries. His article is available at: http://contemplativemotorcycling.blogspot.com.au/2017/11/long-distance-touring-electric-bike.html

In regards to speed if you go for our most powerful 48v1000w motor top speed would be about 55km/h without pedalling. If you pedal and help out the motor, it would be 65+km/h.

Our least powerful 36v250w motor has a top speed of about 30km/h for a rider weighing 70kg. A faster top speed can be achieved if you pedal to help out the motor. Generally speaking, range can vary from 50km to 120km or more depending on which battery you select and how you ride. And of course, there are a lot of variables that can affect the speed, range and performance such as rider weight, conditions, style of bike, tyres, etc.

We have eight different mid-drive motor options, and in addition it’s possible to purchase a programming cable to adjust the output of your motor.

What are the advantages and disadvantages of retrofitting, over purchasing a new electric bike?

The main advantage of retrofitting a bike is that if you already have a bike you love which is the right size for you, it makes sense to add an electric motor and battery to it. Retrofitting will also save money and save space, as you won’t have to buy an extra bike if you already have one.

A disadvantage of retrofitting a bike is that you don’t get a brand new shiny bike!

We saw footage of a really fun looking electric go kart of yours; so you’ve put the batteries to work in other ways too? Can you tell us a little about that?

Yes! The lithium-ion batteries we sell aren’t just limited to electric bikes. They can be used for pretty much any application requiring a power source. They’re the same batteries that are used in electric cars, power tools, laptops and off-the-grid home energy storage (solar panels) as some examples.

What else should people know about your kits or retrofitting bikes, in general?

Once you ride an electric bike there’s no going back. They’re so much fun and also very practical. We love building and riding electric bikes and it’s great seeing our customers get as much enjoyment from them as us. It never ceases to amaze us what our customers can come up with!

Meet the Team:

Pirez Electric Bikes

fat albert
pirez team
PIREZ TEAM (L-R): Nick Isaacs, Katie Galea, Daniel Pereira, Maria Pereira, Lisa Doherty

Why we love these electric bikes:

Among serious cyclists, eBikes can carry a certain negative connotation, particularly among passionate Strava devotees who often fear eBikers uploading their time results without declaring their efforts are mechanically assisted! But, the truth of the matter is, eBikes make cycling more accessible and appealing for more people. And if you build it yourself, then the fun starts even before you get on the bike!

About The Bafang Motor:

Loads of battery options!
Seamless integration

The Bafang mid-drive is a three-phase brushless motor. The motor construction can be divided into four main sections:

ROTOR: This is a permanent magnet and is the moving part of the motor that turns the shaft to deliver the power.

STATOR: This is an electromagnet circuit and is the stationary part of the motor. The energy that flows from the battery to the coils in the stator, interacts with the rotor, which causes it to spin.

BEARINGS/GEARS: The bearings are supported by the motor housing and allow the rotor to turn on its axis. The rotor shaft extends to the reduction gears, which then extend to outside the motor where the load is applied.

CONTROLLER: This is the brains of the unit and controls how much output is generated. It’s also an inverter that converts the DC power from the battery to AC power for the motor.

speed sensor
Speed sensor.
mounted battery
Mounted battery.
Motor and Drive gear.
reduction gear
Motor control system.