What you need to know before buying an ebike conversion kit
You don’t need to buy a brand-new electric bike when you could use a quarter of that money to convert your existing bike. Whether you have a road bike, mountain bike or a hybrid, you can effectively convert your bike to an electric bike with an e-bike conversion kit, but you’ll need to understand some basic ebike terminology to determine what kit to buy…..
The technology of motorized bicycles keeps growing and improving rapidly. An ultra-modern component of an e-bike will probably not be the same in years to come. Besides, e-bikes are subjected to “Moores law” just like PCs. If you did your research on e-bikes a few years ago, a lot of that information will be out of date.
An electric bike conversion kit contains all the components you need -except perhaps the battery- to turn your ordinary pedal bicycle to a motorized bike. We’ll help you familiarize yourself with e-bike terminology so that you will not just be in a position to understand ads better but also understand manufacturer’s guide. This will help you decide which ebike kit – if any – is suitable for you needs and meets your state’s requirements.
Ebike Terminology
- Standard units of measurement for electricity (volts, amps, watts)- most bike motor kits companies use amps, volts, and watts to describe the size e.g. 36V 26A 936W
- Amps measure the flow of the current. You should take note of your battery capacity measured in ampere-hour. This means that the current of an ampere flowing in one hour. The more the Ah the more the run time and the bigger the battery which will cost you more
- Volts is the measure of electric potential. To have more volts, you will need to carry more batteries with you.
- Watts is the measure of the energy capacity. The formula is;
watts = amperes x volts
- Pedal-assist mode -also known as pedelec, only provides power when you are pedaling. You do not have to hold the throttle in a particular position.
- Throttle mode- is similar to how a motorcycle operates. When held in position, the throttle mode gives power to propel your bicycle forward. Some states only allow Pedal-assist ebikes and do not allow a throttle only ebike.
- Motor- is the component that does all the work in an e-bike by converting kinetic energy into electrical energy
- Motor efficiency- most e-bike companies advertise motor efficient between 80 and 85%. It means the motor can convert 80-85% of the kinetic energy into motion
- Chain drive-found in the pedal area, it directs power to the wheels through a chain.
- Regenerative braking- is a mechanism that converts kinetic energy to electrical energy back into the batteries or by creating a braking action.
What is an ebike system made of?
Dc Motor controller: is basically the brain. It takes in the throttle mode and controls current going into the motor. The DC controller cuts off low voltage, shuts off high temperatures and controls the current. Some controllers shut the motor when brakes are applied. Recent motors functions with both sensor and sensor-less motors.
- Throttle
The throttle of an ebike is what allows you to get power from the bike – similar to getting power from a motorbike. If you choose an ebike kit with a throttle, you will have two options: a thumb throttle and a swing throttle. You will get a better control with a swing throttle compared to a thumb throttle.
- Brakes
Several kits today accommodate both older center-pull brakes and the new disc brakes. Ensure your brakes fit your e-bike kit. Kits get shipped with brake levers that shuts power anytime the brakes are applied whether you want them to or not.
- Wheel/rim
All e-bike kits have a hub motor fitted either on a front or rear rim except for the mid-drive motor. E-bike kits include rims with standard sizes of 18, 20,24, 26, and 28 cm.
Power management display (PMD) is the electronic dashboard for measurements such as voltage, watts temperatures, etc
- Wire Harness
All kits come with a wire harness which consists of wire and plugs. Some companies do not provide you with comprehensive instructions – making installation a bit challenging. Some kits come with a disconnect feature for the wiring that goes straight to the hub motor.
E-bike Conversion Kit Guide – Things You Need to Know
You need to know what your intended use will be before deciding on the conversion kit you need. Small geared hub motors will be adequate if you live in a fairly flat area. However, if you live in a relentless steep location, then a mid-drive would do. In the end, the decision you make will be based on your personal needs.
Ebike Motors
Direct Drive Motors
Hub motors are the easiest form of electric bike thrust. The outside of the hub has powerful magnets around it that is essential to the motor. The motor is fixed with the shaft so the body of the motor spins and not the shaft. The bigger the motor the more torque it produces at low speeds. Direct drive hub motors are relatively cheap and more reliable. If you are looking for a high-performance bike on a budget then this is the way to go.
Geared Motors
A geared hub motor is more efficient compared to a direct hub motor. The motor’s planetary gear reduction system that connects stator and the motor case. The motor spins faster for every rotation of the case. There will be no peddling resistance if the motor is off or if it runs out of power. Geared hub motors require very minimal resistance. However, if you ride on the hills a lot, the nylon planetary gears may wear out. The good news is that they are easily replaceable and affordable.
Front hub motor (front wheel electric bike conversion kit)
A front wheel hub motor is far the easiest to install as the process is very straight forward. No need for swapping freewheels or gear cassettes.
Consider choosing a small geared hub for your front wheel electric conversion because they are light in weight and would produce a reasonable torque. Light direct-drive front-wheels are inefficient for front-wheel electric conversion because the motor can be too large to fit into bikes that have disc brakes. Besides, they are heavy.
Rear-wheel electronic bike conversion kit
This type of hub motor is preferred when adding an assist to a bicycle. To change the rear wheel, you will have to remove the gear cassette using a special tool. While the front wheel pulls you while you move, the rear wheel pushes you. Rear hub motors are best for rough roads. There is no problem with wheel spin since the weight of the rider is concentrated on the back wheel. The only disadvantage with this set up is that it is time-consuming to change the inner tube in case of a puncture.
Mid-drive motor
Mid-drive motors are much preferred with more expensive electric bikes. They produce more torque, hence more efficient compared to hub motors. During installation, the bottom of the bicycle needs to be removed. Therefore, it can be challenging for an inexperienced rider. Mid-drive kits are only compatible with a threaded bottom bracket of 68-73mm wide and 33.5mm in diameter. Your bike will have an expensive look when fitted correctly. The only downside is that there is an increased peddling resistance when the motor is switched off.
Which ebike motor to choose - mid drive or hub?
Taking into account all the descriptions above, it all boils down to your ride plans and your budget. In our experience hub motors are simple to deal with in the long run. Remember the direct drive hub and the mid-drive both produce peddling resistance with the motor off. Mid driver motors definitely outshine the rest when it comes to hill climbing. Mid-drive motors have a tidy and finished look compared to hub motor kits that have DIY look with lots of wiring hanging around.
Batteries are one of the most crucial units of an e-bike, without which, you are going nowhere. Battery technology is evolving rapidly so it is good to be informed about the best that are available in the market.
Electric bike batteries; Choosing the right type and how to get the most out of your battery.
Lithium-ion (Li-ion)
Approximately 90% of the market share is captured by these batteries, making them the default battery option. They last long and they generate more power for their weight compared to other batteries. They might be expensive but they have genius-inspired electronic features that make them one of the best in the market.
Lithium Cobalt (LCO)
This is a new kid in the block; a slight variation of Lithium-Ion. It offers high power in a lighter, compact package. It has a very high energy density. For instance, lithium cobalt batteries are used in Optibikes whose manufacturers claim is one of the best bikes with very high mileage.
Lithium-ion Polymer (Li-pol)
This is also a new lithium battery. Interestingly, this polymer can be cast to take different shapes. Since they are not comprised of any liquids, they don’t require the protective cases used on other batteries. The liquid absence improves the stability and reduces the vulnerability to overcharging, abuse, or damage. They are ideal for high-volume and low-energy applications just like in electric bikes.
Lithium Manganese (LiMg204)
They use the same battery technology as the Nissan Leaf Hybrid vehicle. There are claims that it surpasses its Lithium compound predecessors. For example, most Elite Electric Bikes use it and the manufactures are confident that it lasts longer and generates more power than other Lithium batteries
Nickel-metal Hydride (NiMh)
They are not just more expensive than NiCd but also more efficient. They have a little improvement over their equivalents. They last longer and are easier to dispose of. Nonetheless, they are becoming quite rare as the market is being taken over by Li-ion batteries.
Nickel-Cadmium (NiCd)
For the same weight, they have more capacity compared to their lead-acid peer. They also have a longer life span than lead-acid.
Lead-acid (SLA)
Lead-acid batteries are cheap and easily recyclable. The downside is that they are very sensitive and don’t last long. They are not a good battery option for a commuter bike.
F.A.Q’s
- What is the best electric bike conversion kit? Mid-drive is the most advanced and highest power/torque performing kit
- What is the fastest electric bike on the market? Thanks to its mid-drive motor, HPC Scout Pro has an insanely top speed compared to the rest of its competitors
- How do I decide between buying an e-bike or a conversion kit? A kit saves you a big budget while still letting you keep your original bike.
- Is converting a bike to an electric bike expensive? In the USA it would cost an average of $3000-$4000 to buy an e-bike. Some are as expensive as $18000. However, it would only cost around $1250 to convert a bike. Eventually, converting a bike is cheaper than buying an e-bike.
What do I need in an ebike conversion kit?
Now that some of the ebike jargon has been covered…. What exactly will you need in an e-bike kit?
1. Some type of motor as a drive unit or wheel. (For a more professional e-bike with a refined factory touch, consider a mid-drive motor. However these are more difficult for DIY installation)
2. A battery. (Some kits come with the battery – others require the desired size battery to be purchased separately)
3. Sensors and Controls.
4. Preferably Instructions – or check that there are good installation videos on Youtube.
Then all you will need are the right tools for installation, and with a little patience, the finished product will be well worth the time. For easy and reliable installation, you can go for the small geared hub motor conversion kits – or alternatively, get you local bike shop to do the conversion for you.