What you need to make an electric bicycle circuit. How to make an electric bicycle with your own hands from scrap materials

Electric bicycles are in trend today. Even well-known car companies will present a model of a futuristic bicycle of the future, the operation of which is based on clean, cheap energy. Well, those who like to make things with their own hands also do not ignore this topic. Moreover, it is easier than ever to get spare parts for such devices.
Want to see what one of the most budget-friendly electric bikes looks like? In this article we will not only show it, but also tell you how it works and even how much you can buy spare parts for this miracle of technology.
This electric bicycle model is so simple that anyone, even a novice master, can assemble it. This is a great opportunity to test your creativity and crafting skills. Well, the reward will be a completely functional and practical electric bike based on a regular sports bike.

List of materials

Sports bike or regular;
A wheel for cargo carts or mobile equipment, you can easily make it yourself;
Lead battery 12 V/12 A - 2 pcs.;
Toggle button;
Hardware, wiring and some metal parts.

Let's start assembling the electric bike

A special feature of these bicycles is the absence of a rear foot brake. They provide manual braking of the rear wheel using rubber pads and two multi-directional arc-shaped levers. Their compression occurs from the tension of a steel cable connected to the handle on the steering wheel. The principle of the driving module is based on the transmission of torque from the engine to the bicycle wheel through a rubber-coated auxiliary wheel.

Engine preparation

The engine has a regular cylindrical shape, to the body of which two metal mounting angles are welded. It is necessary to attach a wheel to the engine shaft, which will transmit torque when in contact with the tire of the bike.
In size it should not exceed the diameter of the engine body, so as not to overload it during operation. This could be a rubberized wheel for cargo carts, equipment or even.

Installing the engine on a bicycle

Using plates with holes and a small piece of board, we fasten the engine to the bicycle frame with bolts. We center it so that the auxiliary wheel has uniform contact with the bike tire.

To protect against dirt and dust, bicycles are equipped with a fender, which in our case is metal. We leave it in its place, making a hole with a grinder for the wheel of the device.

Electrics

For power batteries, the author chose inexpensive 12 V lead batteries connected in series, suggesting as an option placing them in an old laptop bag. It can be attached behind the saddle, to the side of our device.

We take out the wires from the batteries, connect them in series with the engine and lead them to the toggle switch on the steering wheel. There are no controllers for adjusting the speed; I pressed the button - the full voltage of 24 V was supplied to the motor from the batteries. The simplest toggle switch can be mounted somewhere in a convenient place on the steering wheel.
To protect the driving mechanism of our electric bicycle, we can attach metal plates to both sides of the frame.

It will be very difficult for every person to pedal when going uphill, especially with a long incline. It is no less tiring to ride a bicycle against a strong wind, when even from a descent you need to apply force on the pedals so as not to stop. On straight sections of roads, and especially on slopes, a bicycle has some advantages: quiet operation, no restrictions on fuel reserves, and no state transport registration requirements. Most likely, if electric bicycles were widely available, then twice as many people would use light two-wheeled transport.

Electric bicycle device

To assemble a homemade electric drive or install a purchased kit on a bicycle, you need to know the purpose of the individual parts being installed. In essence, an electric bicycle is a regular bicycle, on which the following parts are additionally attached:

electric motor;
transmission mechanism;
accumulator battery;
controller;
speed controller;
control equipment.

The electric motor can be commutator, with brushes, or brushless, simpler in design, but larger in size with equal power. It is rational to install electric motors on a bicycle with a power in the range of 150-1500 W. Based on the operating voltage, electric motors are selected for 12, 24, 36, 48 V. The higher the voltage, the lower the current flowing through the motor windings and connected wires, therefore, conductors of a smaller cross-section can be used.

You can assemble a belt, chain or friction transmission mechanism with your own hands.

The battery is usually mounted on the rack or in a mount on the bicycle frame. It is better to use maintenance-free batteries without liquid. Lead-acid batteries weigh more than other types of batteries for the same capacity. In addition, acid leaks out of them when the bicycle is tilted. It is wise to install a battery with a capacity of no more than 20 Ah, since larger batteries will be too heavy to carry on a bicycle.

The factory-assembled controller is a rectangular block in an aluminum case for better cooling. The main purpose of the controller is to change the amount of current supplied to the electric motor based on the voltage drop across the variable resistance in the speed controller. The current is regulated by power thyristors or field-effect transistors, which is why they need cooling during operation. Secondary functions of the electronic unit: measure the battery charge level, limit the battery charge current, limit the speed of movement on the bicycle.

The speed controller is actually a variable resistor. For convenience, this rheostat is installed in the usual rotary knob, which is placed on the steering wheel.

Control equipment includes:

circuit breakers;
brake lever with microcontact that turns off the electric motor during braking;
headlight in housing, with power switch, signal, LED indicator of battery charge level;
a sensor that turns on the engine when you pedal.

Types of electric drives

Electric drives for bicycles come in three types:

Frictional.
Chain, belt.
Motor-wheel.

Friction transmission

A similar type of electric drive is found on sale, but is not very popular. The drive assembly with electric motor and battery is mounted on the seat post, above the rear wheel. The transmission of rotation from the electric motor occurs due to the friction of the rubberized roller on the tire. It seems that in such a transfer everything is simple and reliable. But this transmission method works great only on children's electric cars and bicycles, and for daily use on a large bicycle it is not suitable.

Friction transmission has many disadvantages.

The tire of the driven wheel wears out quickly.
It is necessary to maintain increased pressure in the chamber of the moving wheel.
The drive roller slips when climbing a hill or transporting cargo, especially when driving on a wet road or snow.
A heavy drive creates a strong bending force on the seatpost and gradually breaks the bike frame.

A friction electric drive for a bicycle has one advantage - ease of installation.. It is within the power of every person to equip a bicycle with such a drive: just secure the device above the wheel, install the adjuster handle, and you can hit the road.

Belt or chain electric drive

Many craftsmen assemble this type of drive with their own hands from electric motors from washing machines, car starters, V-belts, chains, and heavy lead-acid batteries.

Electric drives with chain drives have disadvantages.

An open gear is subject to increased wear.
This transmission to the wheel is much noisier than that of other electric bicycle drives. The noise of a chain and belt is especially audible when walking a bicycle in a park or forest.
To connect such an electric drive to a bicycle, it is necessary to place a bulky structure on the frame to mount the electric motor and the drive sprocket or pulley.

Electric drive via a chain or belt is very convenient to build a homemade electric bike.

You can connect a chain drive to a multi-speed bicycle transmission. By changing gears, it is easy to adjust the amount of force on the electric motor when climbing uphill, driving through deep sand and snow. When the electric motor rotates at full speed, does not hum, it consumes less current. The battery charge lasts for a long time if you do not overload the electric motor.
It is possible to assemble an electric bicycle with a chain or belt drive that can reach higher speeds than ready-made, factory-assembled options. The existing high-speed chain drive will help you achieve record speed on your bike.
Free choice of installation location for the electric motor, since the length of the chain and belt drive can be changed within a wide range.

We sell ready-made kits with sprockets, a chain, an electric motor, a battery, a charger, a controller, and a knob-adjuster that are suitable for a bicycle without shock absorbers, with a hardtail and full suspension. Only prices for electric sets with chain drive are higher than for sets of electric drives of other types. Kits with chain drive from the Taiwanese manufacturer Cyclone are very popular among buyers.

Motor-wheel

The most common type of electric drive available on the market. In such a device, a brushless electric motor is installed in the wheel hub.

A wheel with an electric motor has many advantages:

It is not difficult to install the wheel motor, both on the back of the frame and on the front of the fork.
You can assemble an all-wheel drive bicycle by installing two wheel motors.
The running brushless motor is almost inaudible.
A bicycle wheel with a large hub looks much better than an electric motor mounted on the frame.

There are several comments on the experience of using the wheel motor.

You cannot install a wheel with a high-power electric motor on an aluminum fork, otherwise the tangential rotational force of the motor will break the fork dropout antenna. The bicycle fork perfectly withstands lateral forces directed from bottom to top. The rear dropouts of the bike are designed for tangential force, which moves the wheel perpendicular to the axis, so you can safely install a wheel with an electric motor of maximum power on them.
You cannot spin a wheel motor with shorted wires coming out of it. The first thing a person does when he picks up a wheel is to start spinning it. When forced to rotate, any electric motor produces electric current. Three thick wires come out from the motor stator and two or more thin ones from the sensor. If these wires are shorted to each other when the wheel rotates, a spark will break between them and damage the sensor.
The electric wheel must be mounted so that the wires coming out of its hub are on the left. Then the wheel will rotate in the right direction.
In many Asian countries, there is a speed limit for cycling - no more than 25 km/h. Therefore, the controller provides a lock against exceeding the set speed. You won’t be able to accelerate faster, even by accelerating the bike with pedals. When the controller is turned off, the electric motor will operate in generation mode, like an electromagnetic brake.

Many kits are sold, which include: an assembled wheel with an electric motor from 200 to 1000 W, a controller, a battery, a charger, control equipment, and a speed controller. You can buy a cheaper motor-wheel kit for a bicycle, which does not have a battery, and sells not the assembled wheel, but the hub with the motor separately. The most popular electric bicycle wheels are produced by the following companies: Electra, Golden motor, Polariss, Yamasaki.

It must be said that now there is no point in assembling an electric bicycle from available components, since you can purchase a proven, reliable electric drive kit for a bicycle. In addition, you can buy a ready-made, beautifully assembled electric bicycle, for example, from the following manufacturers: GRACE, Izip, Sanyo Electric, Schwinn, Yamaha.

Ecology of consumption. Motor: Total interest in electric transport has only been gaining momentum recently - people of all ages and occupations are increasingly puzzled by the question of “inventing” their own electric bicycle.

Total interest in electric transport has only been gaining momentum recently - people of all ages and occupations are increasingly puzzled by the question of “inventing” their own electric bicycle. Sometimes ideas born in hot heads turn out to be incompatible with the harsh realities of life; quite often the “Kulibino” mentality bears fruit, and the result is quite worthy of the pride of its creator.

Many manufacturers have not remained aloof from global trends, and today on the market of components for electric bicycles it is quite common to offer so-called “whale” kits for creating an electric bike yourself based on an existing bicycle. In order for the bike to move without your help, you will need at a minimum an electric motor, a battery and a controller that is responsible for the correct operation of the first two units - all this, and much more, is included in the bike electrification kit. But in order for the newly-made device to be worthy of the high title of a bicycle hybrid, we suggest using the following tips.

Electric bicycle design: components and assemblies

Just as theater begins with a hanger, and dance begins with a stove, so creating an electric bicycle with your own hands begins with selecting a donor. The correct solution to this issue will depend, first of all, on the goals and objectives that the future owner of a bicycle hybrid sets for the designed vehicle.

It is best to take into account the risks of inevitable high loads in advance and use a downhill-class steel frame with a dual-suspension shock absorption system as the basis of the design. This option will be preferable to others if you are going to install a powerful wheel motor - from a kilowatt or more. A direct drive electric motor with a rated power of 1000 Watts will allow you to reach speeds of 40-55 km/h. Considering the large torque and dead weight of the engine, such a drive is installed in the rear wheel, and it would not be a bad idea to strengthen the axle mounting brackets, especially if the frame is aluminum.

When choosing a ready-made battery or creating your own battery, you must take into account parameters such as weight, dimensions, capacity and operating current. The rated operating voltage can be different (36V, 48V, or 72V) - higher voltage and higher currents will allow it to accelerate to higher speeds. If you need reliability and a long service life, choose a battery with high-capacity LiFePo4 cells. If you want to save on weight and cost, take Li-Ion. A capacity of 10 Ampere/hour is enough for about 20-40 km of travel - the amount of mileage depends on the economy of charge consumption, and for many this parameter is in no way compatible with the presence of the throttle.

When the light weight of a hybrid bicycle is more important to you and you are not chasing high speeds, the optimal choice would be a wheel motor with a rated power of 250-350W. Such engines weigh a little and, as a rule, have a built-in planetary gearbox, which contributes to the normal roll-up of the hybrid bicycle when pedaling. The “cruising” speed of low-power bicycle hybrids is in the range of 25-30 km/h. Electric motors

small power is installed in both the front and rear wheels; this does not have a significant significance, except that it is useful for a more uniform distribution of masses. For the same purpose, it is preferable to place the battery in the central part of the frame - the hybrid bicycle will have better controllability and stability. Another option for placing an electric motor - central (in the area of the carriage) - has not yet become widespread in our latitudes, but many leading manufacturers of kits for electric bicycles also have such offers in their assortment.

Standard controllers in inexpensive kits are hardwired by manufacturers and do not provide for the ability to change operating parameters. If you don't need it, you can just enjoy the trip. If you want to tinker with setting up and selecting the optimal parameters for your configuration, take a set with a programmable controller like Infineon. Close attention should be paid to the switching and installation of electrical equipment - high-quality wiring designed for operation at certain currents, reliable connectors, sufficient cooling of the controller, which heats up during prolonged operation and heavy loads.

Security questions

Bicycle hybrids are a relatively new type of vehicle with a fairly wide range of capabilities. In many countries around the world, legislation equates them to bicycles if the engine power does not exceed 350-500 Watts. A more powerful electric bicycle is a different story with its own operating features. Therefore, safety issues sometimes need to be given even more attention than when driving a scooter or motorcycle. Don’t forget about both protective equipment and additional equipment. Even for those who are not going to have fun on the downhill trails, but simply plan to enjoy the surrounding beauty on a leisurely trip, in any case it is worth using a bicycle helmet, gloves and other protective elements that can protect the cyclist from injury in the event of an emergency.

A headlight, a tail light, additional reflectors, rear-view mirrors, a loud sound signal - all this will be useful to you on the road, and will also help other road users to notice you in time. Particular attention must be paid to the brakes - they must be of high quality and capable of stopping your hybrid bike at any time, since at high speed the usual behavior of the brakes changes. And there is no need for this to become an unpleasant surprise for you. Especially considering the increased weight of the bike - the electric drive components will “pull” an additional 12-14 kilograms. And if interest in bicycle hybrids does not disappear after purchasing a starter kit with a 250-watt motor, we can assume that you will soon have a more solid and heavier two-wheeled friend.

In general, as many people there are as many bicycles. Some people prioritize cost, others prioritize reliability, and others are interested in weight or external data. Today, the bulk of requests can be satisfied by ready-made solutions - among the variety of models offered, you can choose exactly the hybrid bicycle that will fully meet your requirements. published

In the conditions of modern development of megacities, when personal vehicles for moving along the streets become burdensome, various types of two- and three-wheeled vehicles are becoming increasingly popular. In the West, special bicycle traffic zones are being created, bicycle parking areas are being organized, and numerous rental points for bicycles, mopeds and electric bikes have been opened. In Russia, many fans of two-wheeled transport are thinking about switching to an electric bike, but they are puzzling themselves with a number of questions:

how to assemble an electric bicycle with your own hands,
where to get the components and necessary parts for modifying an industrially manufactured “great”;
How much will the modernization cost?

Of course, you can also purchase a ready-made model of an electric bicycle. Recently, various electric bicycles have appeared on sale, costing from 56.0 thousand (Volteco Freego model - South Korea) to 175.0 thousand (Dahon Ciao Ei7 model - USA) rubles. To select the best model, you need to study a large market with numerous models of bicycles, or you should trust the opinion of experts and choose one of them.

However, there are many skilled DIYers who find upgrading a regular road bike to an electric bike a lot of fun.

A brief excursion into history

The idea of using an electric motor to drive a bicycle has been in the minds of inventors for a long time. The main obstacle to the implementation of this idea was the lack of rechargeable batteries, which, with sufficient electrical capacity, voltage and current supplied to the load, had insignificant overall dimensions and weight.

The impetus for the intensification of work on the creation of electric bicycles was the widespread use of lithium-ion and lithium-polymer alkaline batteries, which, despite their small size and weight, have high electrical characteristics and a service life that allows them to repeat charge-discharge cycles for a long time without losing quality parameters. Today, various types of these rechargeable batteries are widely used in cordless power tools.

Chinese manufacturers were the first to master not only the mass production of electric bicycles, but also began producing a wide range of components, spare parts and accessories that make it possible to turn an ordinary bike into an electric bicycle.

Peculiarities

Today, in the conditions of urban transport collapse, an electric bicycle is interesting due to its significant advantages over other types of two-wheeled transport, and environmental safety is not the least important. Functionally, an electric bicycle is similar to a conventional moped, in which the gasoline internal combustion engine is replaced by an electric power unit. The power of the electric motor of industrially produced models ranges from 0.25...1.2 kilowatts, while the electric bicycle is capable of reaching speeds of up to 50.0 kilometers per hour. The main advantages of an electric bicycle are:

two modes of movement - using a conventional pedal drive and an electric motor;
the ability to travel long distances using electric propulsion;
compared to a moped and scooter, less labor intensive maintenance and better maintainability;
environmental friendliness of the vehicle, thanks to which in the West owners of electric bicycles receive various benefits.

However, an electric bicycle also has certain disadvantages, the main of which are:

high total weight of the power unit, including an electric motor, battery, additional transmission and control system (electric controller);
long charging time of modern batteries, with their insufficient autonomy;
high price of factory components;
low speed of movement on suburban highways.

Selection of components for conversion

Having decided to convert his bike into an electric bicycle, the owner must take a responsible approach to the selection of components, paying special attention to the compliance (adequacy) of all elements of the electric drive. By saving on the purchase of a battery, you can get an electric bicycle, on which you can ride to the nearest supermarket without recharging, and return back by pedaling. Conversely, an electric motor that is too low-power will not only not allow you to develop the desired speed, but due to its low dynamics it will lose a lot of safety.

To convert a road (city) bicycle into an electric bike, you cannot do without:

You can take the path of least resistance and buy a wheel motor (“MAGIC PIE-3 26”, 17.5 thousand rubles) or a complete electric drive (“BAFANG BBS-01”, 45.5 thousand rubles), which will minimize complexity and labor intensity bike conversion.

If you purchase the engine, battery and control unit separately, you will additionally need:

pulleys (2 or 4 units) from a passenger car electric generator;
driving alternator belts;
additional sprocket - it is better to purchase a kit with a “Bafang 52 T” mount;
freewheel (ratchet, reverse clutch), which is necessary to transmit torque from the engine to the propulsion unit.

What should the frame be like?

The easiest way to install an electric drive is on a regular road bike with a steel frame. It is not advisable to use frames made of carbon fiber and aluminum alloys for electric bicycles.

A controller is mounted on the frame, which should be mounted on an aluminum plate that serves as an additional heat sink/radiator.

Installation of mechanics and engine

Installation of an electric drive on a future electric bicycle depends on the layout of the power unit, and it is easiest to assemble an electric bicycle with a traditional layout - the drive is carried out on the rear wheel. It is necessary to fix the “Bafang 52 T” sprocket on its bushing
, which will require the cyclist to have certain metalworking skills and the presence of a grinder with a diamond wheel and an electric drill. The sprocket disk is fastened to the bushing using four to six bolted connections, which must be secured with locknuts.

The chain drive to the rear wheel is carried out from a freewheel, which is installed separately on an intermediate support.
Rotation from the electric motor to the freewheel occurs through a belt drive assembled from generator pulleys and passenger car belts.
This complicated scheme for transmitting torque from the engine to the wheel allows one to avoid sudden jerks when starting from a stop, and also eliminates the reverse transmission of rotation in the direction of the wheel - the electric motor shaft.

The standard derailleur on the bike is used as a drive chain tensioner.

During the assembly of individual parts and subassemblies, fitting operations are usually required, which are performed using a conventional set of files of various sections.

Installation of electrical equipment

After assembling the mechanical part of the electric bicycle, installing and mounting the engine, battery and controller, it is necessary to assemble the electrical circuit.
Usually this operation does not cause any difficulties, and its complexity depends on the selected components. Particular attention must be paid to the reliability of contact connections, eliminating their sparking and heating.

It is advisable to additionally install an electric signal, which will increase traffic safety, as well as provide power to the headlight and backlight of the bike from the main battery.
Many enthusiasts install LED lighting on their wheels, which increases driving safety at night.

Conclusion

As can be seen from the description, if a cyclist has excess financial resources, free time and certain skills as a mechanic and electrician, converting a bicycle into an electric bike is not difficult. The only thing I would like to warn you about is...

Among the unusual uses of a washing machine engine, the most unusual can be considered turning it into a bicycle motor. A bicycle motor from a washing machine sounds more than extravagant, but looks absolutely exceptional. Read about whether it is possible to produce this “technical artifact” and how to do it in this publication. We warn you right away that the project is technically complex and quite expensive, so if you are not confident in your abilities, it is better not to start.

Drive mechanism

Before you start converting a regular bicycle into an electric bicycle, take a look at the technical potential of your iron horse. The bicycle must have a fairly powerful frame, since it must, at a minimum, support the weight of the rider and the weight of the equipment that will be installed on it. If everything is in order with this, you can begin to remake the bicycle and install on it the motor from the washing machine, drive mechanism, control system and power supplies.

Let's start by designing and installing the drive mechanism parts. Let us note right away that in order to make a homemade electric bicycle from the engine of an old washing machine, we will need a full-fledged metalworking workshop. Well, or at least a lathe, drilling machine, welding machine, as well as an impressive set of materials and tools, including a fairly spacious room where you can conduct experiments.

The drive mechanism will consist of the following elements:

modified bicycle hub;
large pulley;
drive belt from the washing machine;
small engine pulley
motor shaft.

The most difficult thing here, perhaps, is making a large pulley. It’s almost impossible to find a standard part that fits the size, so you’ll have to make one.

From a steel sheet (2 mm), cut out a perfect circle.

We drill small holes in the hub of the rear bicycle wheel, between the spokes. We drill similarly located holes in the steel circle.
We drill large holes along the edges of the steel circle, simply in order to reduce the weight of the part. Because, as noted above, all the equipment together with the rider will weigh a lot, and you need to unload the bicycle frame as much as possible, saving at least a few kilograms.
Next is the crucial moment: it is necessary to weld a 20x4 mm steel strip to the edge of the disk. You need to weld gradually by bending the strip of metal exactly along the edge. This is not the easiest thing, because the welded joint must be perfectly smooth.
After this, we load the part into a lathe and process it again, removing all the irregularities and roughness.
So our part has turned into a full-fledged pulley. Now all we have to do is paint the main part of the drive mechanism and screw it to the rear bicycle wheel.

Important! The thickness of the large pulley will not allow the bicycle wheel to rotate after installation, since the part will touch the frame. It is necessary to either bend the frame or modify it in some other way, depending on the design of the bicycle.

Frame modification

We made a large pulley and adapted the remaining parts of the drive mechanism. By the way, there is no need to redo the remaining parts of the drive mechanism. A small pulley is already on the motor shaft from the washing machine, there is also a drive belt, so we can move on to remaking the bicycle frame with a clear conscience. When modifying the frame for a new electric bicycle, we must take into account that the engine on it should be positioned as rigidly as possible. To do this we do the following.

Attention! When welding the frame for the engine, take into account the height of its seat. It is necessary that the distance between the small pulley of the engine and the large pulley of the bicycle wheel is ideal for tensioning the belt.

We continue to assemble the electric bike. We install the engine on the frame, install the rear wheel with the pulley screwed on, and check the rotation of the wheel. We tighten the drive belt, give small turns by hand, checking that it does not jump off. If everything is fine, we begin to connect the washing machine motor and organize its autonomous power supply.

Motor power supply

We have written and spoken repeatedly about making it work. So we will not focus on this issue again, but will move straight to the organization of autonomous power supply for our commutator motor. Otherwise, our homemade electric bicycle will continue to be driven by the muscular power of the legs.

First, let's figure out whether a commutator motor from a washing machine can operate on direct current? After all, the batteries, which will become the main source of power for the electric bicycle motor, provide direct current, and the washing machine and its units operate from an alternating current network (household network 220V). It turns out there are no problems with this, moreover, the motor from the washing machine works much better on direct current than on alternating current, which, naturally, is to our advantage.

We will select suitable batteries. This may be difficult, since we will need several rather massive batteries, which are difficult to mount on a bicycle due to their size and heavy weight. The best option is eight compact 12-volt motorcycle batteries, which together produce a voltage of 96V. But there is a problem - even such batteries take up a lot of space and, in total, weigh quite a lot, and it is not clear how to place them on the frame of an electric bicycle.

After much thought and a whole series of unsuccessful experiments with battery boxes, it was decided to distribute the batteries evenly throughout the frame, hanging the electric bike with them like a Christmas tree with toys.

Firstly, as you can see in the picture above, the bicycle frame had to be strengthened once again so that it could withstand the additional load. This, unfortunately, led to the weight of the “iron horse” once again increasing, but nothing can be done about it.
Secondly, 8 separate battery mounts had to be welded to the frame so that they could be securely fastened.
Thirdly, we had to literally cover the entire frame with wires to connect the batteries to each other and to the engine.
And fourthly, we had to once again improve the aesthetics by repainting the bike frame almost completely.

Control block

There are still a number of technical difficulties that we have not yet considered - how to control the engine speed, how to prevent the current from rising to the limit values when starting the electric bike and during its acceleration, and, finally, how to monitor the charge of the batteries while driving. The electric bicycle control unit, which we need to assemble, will help resolve these difficulties. We will need:

32.5 kHz switching downconverter.
Variable resistor.
Microcontroller ATtiny26.
Measuring resistor.
Chip IR2127S.
Three power transistors type IRFB33N15D.
Three diodes type 10CTQ150.
Charging from a mobile phone.
DC-DC converter P6AU-1215ELF.
Red and green LEDs.
Automatic 6A.
Plastic case of suitable dimensions.
Metal radiator from a computer motherboard.

We will not describe the process of assembling the control module, and there is no need for this, since all the necessary information is presented in the diagram above. You just need to read this diagram, understand it and reproduce it on several printed circuit boards. The result should be something similar.

The board must be placed in a compact waterproof plastic case, with a radiator screwed to the bottom.

We did not find a suitable housing for the module, so we had to use what we had. In order for the control module to start working, you need to turn on the machine, turn the “gas handle,” that is, a variable resistor mounted on the handlebars of the electric bicycle. After which the engine will begin to smoothly gain speed, and the green LED on the module will light up.

If the batteries are completely discharged or their capacity is insufficient, the red LED will light up, after which the circuit will be de-energized after a few seconds. You will have to travel on your own until you can recharge the batteries.

Tests and their results

The time has come to test the “infernal machine” on which so much time, labor and money have been spent. We approached the tests no less scrupulously than when making a homemade electric bicycle and carried them out in three stages:

Driving on an ordinary relatively flat road (half asphalt, half dirt road) at a speed of 18 km/h.
Driving on smooth asphalt with slight ups and downs at a speed of 25 km/h.
Driving at maximum speed on smooth asphalt without ups or downs.

As a result, in the first case, accelerating to 18 km/h and maintaining this speed, we were able to drive 27 km on a single battery charge on dirt roads and broken asphalt. The muscular strength of the legs was practically not used. There were no ups or downs along the way.

Having ridden an electric bicycle on flat asphalt with slight descents and ascents at a speed of 25 km/h, we managed to set a record of 19 km on a single battery charge. And finally, maximum speed tests showed that our homemade electric bike is capable of accelerating to 30-35 km/h, this, of course, on flat asphalt, without descents or ascents.

For your information! The weight of the rider testing the bike was 96 kg.

It is noteworthy that if we help the engine by rotating the pedals, we can relatively easily reach a maximum speed of 45-50 km/h, and if we try, we can reach 60 km/h. At the same time, the batteries discharge faster, after about 10-15 km of such a sprint.

In conclusion, we note that to make an electric bicycle from a washing machine engine yourself, you will need at least several months, a workshop, a lot of strength and patience, as well as money. By the way, we spent about $700 on the project, provided that we did not have to purchase a bicycle and parts of an old washing machine. If you are determined to make your own electric bike, go for it, we can only wish you good luck!