Retrofit electric bike – how to turn a bio bike into an e-bike

You would like to have an e-bike, but your wallet does not allow it? The alternative is to retrofit an e-bike, at least if you go by the manufacturers of bike conversion kits. You can find them in large numbers and at different prices in stores. Here we look at how they differ, what you should look out for in advance, and what you need to succeed in your bike conversion. We also ask the key question, "Is it even worth it, or isn't it better to save up for a new e-bike?"

Wie du aus einem normalen Fahrrad ein E-Bike machst

A new e-bike is expensive. Especially if you are looking to save money and have a bike you are happy with, it might seem tempting to upgrade your bicycle. You can get bike conversion kits in a variety of price ranges. Nevertheless, is it worth it?

That depends. Here is what you need to know and how to go about converting your bike into a pedelec.

Converting your bike to an e-bike: Important questions to ask beforehand

Before getting seriously into bike-to-electric-bike conversion and buying an electric bike conversion kit for your bike, you should answer some basic questions.

  • Stability: the motor and a battery add weight. In addition, there are the forces to which the bike is subjected by the motor drive. It is therefore crucial that your bicycle is robust, especially the frame and fork. Also, note that the material of old bikes can show signs of fatigue. If your bike was robust 8 years ago, it is not necessarily so today. Here a consultation can make sense.
  • Brakes: The extra weight also challenges the brakes of bicycles. This is especially true if you are traveling significantly faster than before, supported by the motor. Brakes with cable are quickly overtaxed in this situation. Replace them rather against the hydraulic rim or disc brakes.
So it can be stated:

Converting to an electric bike is an option if you have a good, sturdy, and not too old bicycle. It is better not to load the student bike you inherited from your dad with a motor and a battery.

Tips for choosing an e-bike conversion kit

Are you sure that your bicycle is suitable for transforming into an e-bike and want to spend the money on an appropriate kit? Then we come to the question of what you should look for when choosing.

Each of these variants has its advantages and disadvantages

Most who want to convert bikes to electric bikes opt for a rear motor, but a mid-motor is also good. We would only advise against front-mounted motors for safety reasons and because of the poor ride feel.

What else you should look out for

Once you have inspected the battery and motor, there are two things you should pay attention to:

  • Mounting: We have already addressed this point. How easy or difficult it is to convert a bicycle into an electric bike varies greatly. Especially if you are not a born screwdriver, find out how complex the installation is.
  • Compatibility: Not every conversion kit fits every e-bike. Therefore, make sure that the kit is compatible with your bike.

Finally, of course, the price also plays a role. There is no hard and fast rule here, except that caution is advised with bargains. Also, always remember that the conversion is only worthwhile if it is not more expensive than a new electric bike.

3 manufacturers of electric bike conversion kits in comparison

Meanwhile, so many manufacturers offer conversion kits for e-bikes that we cannot possibly list them all.

But we want to pick out three recommendable ones as examples:


Still comparatively new as a manufacturer of retrofit kits is the company Ansmann. However, it has already made a name for itself in the field of battery packs and rechargeable batteries. With Ansmann, you have the choice between different drive types and mounting locations. At around 1000 euros, the kits are in the midfield in terms of price. In return, they offer reliable quality, a pleasantly quiet motor, and high compatibility.


Bafang is known for its wide range of rear and front motors for converting bikes. In some cases, motors of the Chinese manufacturer are also used as original equipment for e-bikes. Here, you will almost certainly find a compatible model and can choose between different performance levels and equipment, including modern on-board computers. Nevertheless, many retrofit kits from Bafang are not expensive and easy to get. Accordingly, Bafang kits are popular. Only the installation requires patience and skill and must be done by yourself. In addition, not every Bafang set complies with the STVZO. If you are unsure, get advice!


You will have to dig deep into your pocket for Pendix conversion kits, at least if you want to cover longer distances. Then the fun costs around 1500 euros or – for even more range – 200 euros more. However, there is hardly an electric bike conversion kit that looks as appealing as this one. In addition, you can switch between different driving modes directly on the battery and Pendix also sets standards in terms of volume. In the meantime, there are also two significantly cheaper variants from the same supplier, but with a very limited range. They are suitable, for example, if you only want electronic support on inclines. The Pendix eDrive1000 is suitable for tours lasting several days. However, this device costs more than 2000 euros.

Think about the theft protection for your new e-bike

When you convert a bike into an e-bike, its value increases. Unfortunately, not only for you, but also for bike thieves. It is, therefore, all the more important that you protect your pedelec well against theft.

Three components, in particular, are essential for e-bikes:

  • at least one high-quality lock, perhaps with an integrated alarm system
  • one or more component locks to protect the battery and co. from theft
  • a GPS tracker to track your e-bike live and get it back in case of emergency
Fahrrad vor Diebstahl sichern mit einer Kombination aus Schloss, Alarmanlage und GPS-Tracker

To equip your retrofitted pedelec with a GPS tracker, you can get the BikeTrax GPS tracker from PowUnity in several variants:

  • Engine-specific trackers, for example, for an electric bike with a motor from Bosch, Brose, Shimano, or Yamaha.
  • The GPS Tracker Universal, which lives up to its name and is suitable for a wide variety of technology applications where a connection to a power supply is possible – perfect for a converted electric bike.
  • In the near future, there will also be a GPS tracker specifically for motors from Bafang.

With all variants, you benefit from the following advantages for modern theft protection:

  • You are immediately alerted via the associated app if your electric bike moves unintentionally.
  • You can track your bicycle throughout Europe via a modern app in real-time and share the location data with friends, family, or the police, for example. So the chance is high that you will get a stolen bike back, a big difference from a bike without a GPS tracker.
  • You also benefit from valuable additional features like a bike tracking sheet in the accompanying PowUnity app.

Retrofit e-bike – advantages and disadvantages

Now we come back to a question we raised initially: Is it even advisable to convert a bike into an e-bike, or isn’t it better to save up for a new pedelec right away?

In fact, a conversion has some advantages:

On the other hand, there are also disadvantages:

Conclusion: Conversion is possible, but not always worthwhile

Converting a regular bicycle into an electric bike with a top speed of 25 km/h is not witchcraft. Depending on the provider or bike conversion kit, the installation can be done without a dealer’s prior knowledge and support. In addition, you can choose between different systems, and you do not have to do without a GPS tracker for modern theft protection.

However, this method is especially suitable if you own a high-quality bicycle that you have grown fond of and want to convert it into an e-bike in the long term. Otherwise, it might be better to take a look at affordable new e-bikes first. After all, the conversion is usually not that much cheaper and with a new model, you can be sure that all components complement each other for a good riding experience.

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