An ebike conversion kit is made up of a series of components to install on your normal bike, and turn it into an ebike.
The idea is that if you already have a good bike – maybe one that you are also emotionally attached to – then you may prefer to keep it and turn it into an ebike, rather than buying a new ebike; in this way, you can also save some money, as the cost of a kit is lower than the cost of a new ebike. A kit also allows you to electrify some particular kinds of bikes which don’t have a ready-made electric version, such as recumbent bikes, or tandems.
If that is not the case, that is if the bike that you already own is not in very good conditions, then buying a new ebike may in most cases make more sense. You will have a frame that is designed to accomodate all the electrical components, and you can be sure that everything will work smoothly.
Having said that, there are many excellent kits to buy, and if you pay attention to their technical specs – and your bike’s specs – you can build yourself a functional ebike, and have fun by dusting your DIY skills.
There are many different ebike conversion kits, to suit the tastes and needs of everyone. The simplest require you to just replace one of the wheels of your bike; other kits will allow you more flexibility, but also require more attention to set them up.
The price of an ebike conversion kit can vary widely, from a few hundred €/$ to about 1000€/1200$, or even more; the price is determined mainly by the quality of its components. A kit has everything you need to turn your normal bike into an ebike, that is: a motor, a battery, a control unit, and a display for the handlebar. Please refer to the pages where we go in depth into these components to better undestand this article.
Some kits – most famously, the Copenhagen Wheel – have most of these components fitted inside a special wheel, and all you have to do is replace your bike’s wheel with the one provided by the producer of the kit. This can be useful if your aim is to just pedal around town for relatively short trips; putting all the weight on the wheel (the Copenhagen Wheel weighs 5,9kg/13 lbs) is not ideal – imagine the stress on the hub and spokes when you hit a pothole with a wheel that heavy.
If you want more flexibility, range, and power, you will have to choose a different kit, one that will make your bike resemble more an ebike, with motor and battery on different places. This will allow you to have a more balanced distribution of weight, and a series of other advantages, such as the possibility to easily detach the battery to recharge it.
There are dozens, probably hundreds of kits out there, and you can choose pretty much any configuration that you like: hub motor (front or rear) or mid-drive motor, of different power; you can put the battery on the rear rack, on the down tube, or even under the saddle (for small batteries when you don’t need much range).
Hub motors, and especially front hub motors, are the easiest to set up; with a front hub motor it’s also easy, if you suffer from a puncture, to remove the wheel in order to fix it; as for the location of the battery, try to balance the weight: if you choose a rear hub motor, avoid a rear rack battery: your ebike will be much more balanced if you go for a down tube battery.
These few lines were just some general advice concerning motors and batteries when you choose a kit; please refer to our in-depth pages on ebike motors and batteries for more information, as what is written there can be applied to ebike kits as well.

Some kits – such as the recently announced Sunstar Virtus – can easily be removed and swapped between bikes. If you have more than one bike, or if you think you will often ride without assistance, then consider these kinds of kits.
More advice concerning ebike kits
The most important thing to consider when buying an ebike kit is whether it will fit on your particular bicycle. This is true especially for mid-drive kits, where you have to make sure that the size of the bottom bracket (the bit that allows the pedals to turn) is compatible. A serious ebike manufacturer should be able to assist you, giving precise information on the required sizes, and advice on how to measure your bike to make sure the kit will fit. If you’re not 100% sure, we suggest you seek the help of a local bike mechanics: you don’t want to spend 800€ on a kit only to find out it doesn’t fit on your bike.
Same goes for actually installing the kit. The manufacturer should give you advice on how to do it, ideally providing a video guide. If you know you’re good at DIY and you understand the instructions, go ahead and you won’t have problems. If you’re not sure though, get help from a qualified bike mechanics before you break anything.
Ensure the kit comes with a decent warranty, especially on the battery, which should start to fade only after 1,5 / 2 years of continued (and correct) use. If the manufacturer provides only a 6 months warranty on the battery, look for something else.
Have you built yourself a wonderful custom ebike, using a conversion kit? Do you want to show it to the readers of the Ebike Portal? Then get in touch and send us a few pictures and some lines of text describing your project!