Before purchasing an electric bike conversion kit you will need to decide on what you want it for. Consider the questions below to help you decide on the best kit for your needs.
- Do you want it to ride like a motor bike, as in you don’t have to pedel, just hold on and go fast?
- Do you want it to be light and just like having a professional athlete helping you pedel when going on bike rides, but easily be able to ride it without the motor going?
- Do you want to spend hours tinkering and customizing your electric bike kit or do you just want to plug it all together and ride?
- How much weight are you willing to add to your bike?
- How far are you hoping to ride each day?
- Are there lots of hills or is most of your riding fairly flat?
- How much money do you want to spend?
The main Types of Electric bike conversion kits
Front in Hub Motor
- easy to install
- will fit most bikes
- good balance putting some weight in the front
- Gives the all wheel drive effect (pedels to rear, motor to front)
Rear in Hub Motor
- A little more difficult to set up with gears etc.
- Better traction up hills
- Feels nicer having the power in the rear wheel
- Can start to add too much weight to the rear wheel
Geared Drive Direct to Rear Wheel
With this setup you bolt an electric motor to the bike frame (usually just above the back axle) and run a chain to your rear wheel
- Can be more efficient on power
- Often cheap
- They look a bit ugly and can be bulky
- They can be fiddly to set up often requiring some extra parts and ingenuity to get attached correctly
Geared Drive to pedal crank
With this setup an electric motor is bolted to the bike frame near the pedal cranks, and an additional cog is added to the pedal crank cluster, then a chain from the motor drives the cranks.
- Motor drives through the gears, giving you great hill climbing and speed on the flats.
- More efficient if you use the gears correctly
- More wear on chain and sprockets
- This requires some considerable engineering skills to set up
- Requires many parts.
Technology Available in Electric Bikes
eBike Regenerative Braking
It seems to be the buzz with consumers to get a bike with regenerative braking but the maths does not add up. The the extra energy gains in your battery are very small and the money would be far better off spent on other areas, better batteries, a more aerodynamic design, etc. So with current technology, costs and the laws of physics and chemistry it is not worth pursuing yet. read more at this website
Brake Cut out Switch for Electric Bike
This is a feature some bikes have, it can be important on high powered bikes because if there is an issue with the throttle sticking on, your brakes my not be able to stop you adequately so this switch shuts off power to the motor when you use the brakes. They add another thing to install so if you are using a lower powered electric bike I would say it is not worth installing one.
Pedal Assist Electric Bike
Pedal assist bikes have an electric motor that automatically starts as you start pedaling, making riding them simple. But the issue is you may not always want the motor to start and this will also more rapidly drain your battery. A neat idea but overall probably adds too much complexity for little gain.
Batteries for Electric Bikes
The battery market for electric bikes and many other gadgets is huge at the moment. With Hybrid cars, mobile phones, laptops and many otehr gadgets requiring batteries there is a lot of motivation for businesses to develop the next “best battery”. Currently the main battery options are:
Sealed Lead Acid – SLA
Sealed Lead Acid (SLA) Batteries are cheap to produce, most ebikes have used sealed lead acid batteries in recent years. They are virtually maintenance free but they are heavy and take some time to charge. As the newer technology gets cheaper it is likely they will become obsolete very soon.
Nickel Metal Hydride – NiMH
NiMH batteries are fast to charge plus they are lighter and less toxic than SLAs. They have a high energy density. But performance is reduced in cold weather and they need to be fully discharged at regular intervals to maximize battery life. So they do perform better that SLA batteries but are still not perfect.
Lithium batteries are light and maintenance free. They last a long time and can be quickly charged. The chemistry in them can be complex and some verieties can be fairly unstable so the need to have a battery management system built into them to ensure they aren’t over charged or discharged. There are many different varieties of Lithium Battery
Lithium Polymer Batteries – LiFePo4
The Lithium Polymer battery is probably one of the top styles of batteries for electric bikes at the moment. It is light, holds lots of power, and maintenance free. The better brands are claiming 2000 cycles without significant degrade in performance. It can also be drained completely or partly with out damaging it. Where as Lead Acid batteries will be degraded if they are run completely flat too often or NiMH will be degraded if they are not drained regularly. If you want excellent power to weight and no maintenance these are the batteries to choose.
Price is most often the deciding factor when choosing your batteries as they are often the most expensive part of an electric bike conversion. Lead acid batteries are the cheapest going up to Lithium Polymer batteries. Currently you will be looking at between $150 to $1000 for a battery.
Types of Motors For Electric Bikes
Brushed Motors have been around for a while, they are larger heavier and noisier than the brushless motors and they need occasional servicing. So it is likely they will be phased out. But they have been great performing motors and have excellent hill climbing ability and are renown for being very durable in demanding circumstances.
Brushless DC motors are generally smaller lighter and quieter than brushed motors, which generally make them the best choice for ebikes and are probably one of the most common seen in current electric bikes. There are currently newer versions of these motors, sensorless brushless motors and the permanant magnet brushless motors which are coming onto the market. These are still in their early stages of development but may prove to be the market leaders in the near future.