Electric bike with your own hands - it's possible! How to build your own electric bike

Every year the maintenance of personal vehicles in the city is becoming more expensive. Because of this, many townspeople prefer to switch to a bicycle for the summer. As a means to travel to work or long walks in the countryside, this transport is ideal.

Unfortunately, the infrastructure conditions of our cities and other settlements are far from ideal: often there are not only banal paths for bicycles, but even there are no decent public roads. So if you want to use a two-wheeled friend to travel to work and not only often have to face the fact that by the beginning of the day you arrive tired and soapy.

Strange as it may seem, it is possible to considerably facilitate the conditions of your trips by putting a powerful and compact electric motor on your technique . Today we will design the electric bicycle with our own hands. With adequate equipment and time, this is more than realistic.

A bit of history

If you remember, in the recent past it was difficult to imagine a compact enough and light battery that could provide the movement of something heavier than a children's toy car within a hundred meters.

Moves in this direction began only after the widespread introduction of Ni-MH (nickel-metal hydride batteries) in which potassium hydroxide was used as an electrolyte.

It turned out that such batteries are able to accumulate many times more energy than standard acid elements, and their service life is much longer. In addition, with the improvement of production technology, it quickly became clear that their cost is not so high.

Around the same time, many "self-made" and began to visit the idea of how they would make an electric bicycle with their own hands. And then a miracle happened: the ubiquitous Chinese began to produce not only batteries on the industrial scale, but also all the other details and mechanisms by means of which it is possible to quickly turn an ordinary bicycle into a kind of electric "meteor".

Components and their cost

Of course, first of all we need an engine, which in foreign stores can be bought for about two thousand rubles. Next you will have to purchase its controller, the cost of which is approximately one thousand rubles.

Do not forget about the battery pack (also about a couple of thousand), as well as a servo-tester and a quality charger. Together they "stretch" again for a couple of thousand rubles. As for the battery, it is better to buy the product at 5000 mAh minimum.

In addition, there are all sorts of things like power wires, connectors and a wattmeter, you can buy them in any store for electricians. Their price varies depending on the manufacturer, so it is difficult to bring here any specific figures.

Other accessories

But it's too early to relax! Before you make an electric bike, you should buy four pulleys from the VAZ 2108 generator, as well as a pair of generator belts from it.

In the store for bicyclists, we have to get a frivolous, a couple of bushings and the highest quality chain. Do not forget about the gear selector and the 52T sprocket. Among other things, you will need a diamond disk for the UWB, screws, nuts and clamps, which are better to buy with some margin.

Thus, everything will take at least 12-13 thousand rubles. If there is such an opportunity, it is better to purchase the most high-quality components, but in this case the cost of the project can significantly increase.

Mechanics

We begin to make an electric bike with our own hands with its mechanical component. Needless to say, all the work should be done as high as possible, since your own safety depends on it.

Suppose that your car will be equipped with a traditional rear-wheel drive. To ensure the proper twisting force, we just like the asterisk 52T. To attach it to the bushing, you will need a diamond disk from the UCM with a diameter of 15 cm.

The hole under the bushing is drilled with a drill and file, relying on our own strength. To fix all this construction it is possible, using standard "lambs" of the appropriate size. Of course, it is worth thinking about balancing, otherwise at speed you are waiting for extremely sharp sensations.

By the way, you did not ask yourself the question, why did we buy the frivol? We answer: this is one of the most important elements of the design, as it prevents the transfer of torque from the wheel to the engine, which can lead to unpleasant consequences.

Take into account that the standard chains (for you, after all, an ordinary road worker?) Do not sit on it, so the teeth will have to be slightly sharpened. To fix it to the transfer sleeve with a diameter of 10 mm, you have to buy an adapter in the bike store or go in search of a normal turner. By the way, without it, an electric bike with its own hands will be difficult to do in principle.

The standard speed selector is used to create the desired chain tension from the freeload to the driven sprocket. Maximize the design, since the strength of the trip depends on its strength.

Important! The torque from the engine should be transferred in stages in order to avoid deformation and destruction of the sprocket, which is simply not designed for such loads in an ordinary bicycle. Just for this, and use those pulleys and generator belts from the VAZ 2108, which we bought earlier.

A bit about the frame

We did not accidentally mention that in the light of the construction we are considering, it is preferable to use conventional road bike models. Since the power of the engine can be very decent, we strongly do not recommend the use of carbon and aluminum frames. It is best to use ordinary steel, widely used in the manufacture of "Ashanbayks."

Electrics and Electronics

Having dealt with the mechanical part, we pass to the "heart" of our two-wheeled friend. Consider how to mount the motor for electric bike and other important details.

Let's start with the controller. Mount it better to the frame, and in this area it is desirable to slightly scrape off the paint and put an aluminum plate smeared with thermal paste. This will allow not to think about its cooling, which is very important during summer pokatushek.

Take care of safety!

The servo-tester should be switched to manual mode: it is useful for setting the optimum engine power. To power it, it is recommended to use the L7805 chip. To the bike, if necessary, gave out all possible power, we recommend somewhere on the steering wheel (in a convenient and easily accessible place) to arrange the simplest reed switch.

In order to avoid sharp jerks in such cases, which are fraught with the detachment of the teeth on the sprocket, we recommend putting a voltage divider on the pair of resistors conjugated to a capacitor of 100 μF (ideally) on the input of the servo-tester. So you can ensure a smooth increase in speed for about 0.5-0.7 seconds.

The wattmeter is best placed on the steering spider, which will allow you to quickly monitor the consumption of electricity, in advance to make changes to your route. The very same batteries for electric bicycles will be optimally carried in the seat bags. So you will be able to change them to the fresher as soon as possible, and access, if necessary, will be greatly simplified.

Do not forget that your vehicle can accelerate to a decent speed. Proceeding from this, be sure to provide at least a simple sound signal, which in advance will warn other road users of your approach.

Do not do that!

On the Internet, you can find the statement that an electric bike with its own hands from a screwdriver will save you from buying all of the above components. This is not true.

Let's see: even a 600-watt screwdriver without intensive pedal assistance will not climb every hill, and if you look at the wear of its mechanism ... In addition, a suitable mechanism for strength will cost very, very expensive, even if you do not take into account the cost of branded batteries .

In a word, it's better to spend money on something more useful.

Some notes on operation

Before you make an electric bike with your own hands, it's best to put more money on powerful batteries. At the very beginning of the article, we talked about a 5000 mAh battery. It will be enough for about 8-10 kilometers of the road, subject to rare accelerations up to 40 km / h. The average speed should be about 18 km / h, which is quite decent and enough for comfortable movement around the city.

Here's how to build an electric bicycle with your own hands!