Homemade electric bicycle. DIY budget electric bike. Benefits of using a wheel motor on bicycles

This article will talk about how you can turn a regular bicycle into an electric one with your own hands. Such a bicycle will run on a battery, which, when discharged, can always be recharged and then ride on. Of course, there are already many ready-made solutions for this kind of homemade product, for example a wheel motor, but here everything is assembled from scratch.

According to the author, the homemade product fully met its expectations. Since the engine used here is not very powerful, the bike cannot move from a standstill; you first need to accelerate it with your feet to a speed of 10-15 km/h, which is not so difficult. Well, then the electric motor comes into action, which keeps the bike moving and you no longer need to turn the pedals. The electric motor accelerates the bike to 34 km/h when moving in a straight line.

The bike consumes 100-300 watts when moving on a straight road. When driving downhill, consumption increases to 600-800 watts; to save money, you can help with your feet.

The peak current consumption of the motor was 1200 watts.

Materials and tools for assembling a homemade product:
- electric motor type 6354 kv200

- ESC speed controller

- wattmeter (copy of Turnigy 130A);

- battery type LiPO 6S 22.2V 5a-h;

- bicycle throttle (controlled with your thumb);

- brake handles (they have a pressure sensor);

- rear trunk (used as a structural element);

- 16 tooth ratchet;

- gears and belt (ready-made).

Bike Upgrade Process:

Step one. Sprocket installation
In most cases, the sprocket is attached to the spokes, but the author decided to abandon this design. As a result, the sprocket was bolted to the brake disc. On the disc you can also see six screws in a circle and two closer to the center of the brake disc. These screws secure the threads so that the disc does not unscrew while driving.

Step two. Installing the ratchet
The ratchet is installed on the cup from the carriage; a ring from the original cup is used for fixation.

Step three. Rear hub
The rear bushing acts as an intermediate shaft. It is installed in a U-shaped section of professional pipe.

Step four. Installing a Large Gear
A pin is used to secure the gear. Otherwise, the bushing will clamp itself with cones. There is a groove in the gear and the pin fits into a hole that is in the shaft. As a result, the pin fits into the groove of the wheel.

Step five. Small gear
To fix the small gear, two goujons are used.

Step six. Engine Installation
To mount the engine, a standard crosspiece is used to an L-shaped structure, which the author found in the bins.

Step seven. Attach the chain tensioner
The chain tensioner is attached to the side of the trunk. Everything is mounted on a structured plate made from a thick sheet of aluminum.

General view of the bike

Step eight. Homemade electrical circuit
How the circuit works can be seen in the picture. It has been slightly modified in comparison with the original. So, for example, the variable resistor was removed from the servo tester and a hall sensor from the throttle control knob was installed in its place. The author installed a 1 kOhm boost resistor in the button circuit; without it, the modes switched spontaneously, probably due to interference.

Another nuance of the electrical part is that the author separated the power plus and the measuring plus. Also in the future, it makes sense to install an isolated 5V to 9V converter, due to the fact that there are underestimated power readings.

As for the battery, it works without BMS. To prevent overdischarge, the author used a battery monitor that was set to 3.3 V. When the voltage gets too low, the device starts making a sound.
The battery is charged with an IMAX B6 clone, using Li-Io mode with balancing.

An electric motor for a bicycle - this is precisely the product that small workshops and online stores have begun to promote in recent years as an alternative to electric bicycles, which are already quite widely represented on the market. A separate motor can significantly reduce the cost and lighten the design of the resulting mechanism, because most electric bicycles are clumsy and heavy. They are not aimed at keen cyclists, but at a light walking style, so they are equipped with dubious frame configurations and very heavy batteries.

Why are engines needed?

While skiing, especially on long climbs, everyone thought about what they could connect to the chain in the hope of making their work easier and finally overcoming a difficult section. This is why electric motors are installed for bicycles. They allow you to supplement the athlete’s efforts to gain and maintain high speed, as well as maintain strength in problem areas.

The engines come in different designs and powers, but follow the same principle - they are installed on ordinary bicycles, after which they transmit force to the wheels in one way or another (depending on the type).

Types of electric motors

Electric motors for bicycles do not come in a variety of designs. In fact, due to the fairly simple design of the bike itself, there are three types.

Motor-wheel

The most popular and easiest to install engine.

Wired motor-wheel

In fact, the engine is installed on the wheel, or, in more expensive versions, it itself is supplied in the form of a wheel, with spokes attached directly to the engine. This arrangement has several advantages:

simplicity of the device - minimum wiring and problems;
good appearance - sometimes you cannot notice that the bike has an engine;
high efficiency - minimal losses for energy transmission;
low location that does not increase the center of gravity.

The list of disadvantages includes high weight and some difficulties in operation (replacing and connecting batteries).

Chain motor

This is the lightest engine. It is connected to the chain as an additional element, installed in the center of the frame and is very convenient to use, but installation will require precise calculations and the purchase of an additional chain.

Pros of this engine:

low relative cost;
light weight;
ease of battery connection and maintenance;
use of a common gear shift unit.

Disadvantages: labor-intensive installation and increased noise when the engine is running.

Friction drive

A legacy of “old” mechanics, when electricity on a bicycle was generated by a dynamo on the edge of the tire or rim. Similarly, an outboard friction drive transfers energy to the wheel using a pressure roller. Such engines are aimed at recreational and children's models, as well as non-professional buyers.

Friction motor from a famous brand

While the only advantages that can be highlighted are the absolute ease of installation and use, as well as (for some models) low cost, friction drives have many disadvantages:

very low efficiency;
noise during use;
bulky and inappropriate appearance - usually instead of a trunk;
tire wear during use.

Self-installation

Of course, it is easy to purchase a ready-made electric bike. It is more difficult to trust a workshop to install an electric motor on your classic bike. But the most inexpensive and, most importantly, interesting way would be to install the drive yourself.

Installation kits

The popularity of homemade electric bicycles is growing, and many manufacturers offer ready-made kits for installing an electric motor on a bicycle. Kits with a motor-wheel are especially popular. This type of drive does not require special knowledge for installation, it is easy to manufacture and sells well.

Bicycle conversion kit

There are also more serious kits intended for workshops, which include chains, additional rollers and other elements. Often motors come with extra batteries. In addition, a homemade chain motor can be made literally from available materials.

There are expensive kits with friction devices that are positioned as a ready-made “install and use” product for those who do not want to seriously understand mechanics. True, due to the price, such sets are not particularly popular.

Installation process

The most difficult part is the design and installation of a chain bicycle electric motor. If only the electrical part is supplied in the kit, then very serious preparation will be required before installation. So, the installation sequence:

install the engine bracket;
install the engine;
install an additional star and roller (or two, depending on the configuration);
measure the required chain length;
adjust the size of the chain and assemble the structure;
check engine operation;
check operation while pedaling.

If everything is successful, the chain motor is installed!

Layout example for installing a chain motor

For a set of motor wheels everything is simpler:

remove the original wheel;
install the wheel motor;
secure the battery bracket;
make wiring for the battery and for the control panel, if there is one.

As a matter of fact, after that you can go. If for a chain type installation (with preparation of materials) may take several days, then an hour will be enough to install a motor-wheel. In the case of friction mechanisms, some of them are removable in design, and even an elegant girl can install them with her own hands.

Manufacturers

Since the devices are not so complex, there are a huge number of manufacturers, and due to the limited popularity of their devices, many have not received the fame they deserve. Most companies producing electric bicycle motors are located in China:

Bafang is a fairly well-known company that produces a wide range of electric motors, not only bicycle ones;
Cyclone is a Taiwanese company that stands out for the quality and power of its kits;
Bosch – German quality, German prices. Manufactures chain drives. It has not been on the market for long, but has already gained recognition;
Golden motor is a classic Chinese manufacturer (low prices, low quality, many nice additions and decorations);
MXUS is a Chinese company that has been exclusively dedicated to electric bicycle drives for 20 years.

Conclusion

An electric bicycle motor is a great device for upgrading your bike. An inexpensive set will ensure fast driving and overcoming obstacles, and powerful devices will make riding unforgettable. The ability to install the motor yourself may appeal to anyone who is interested in technology and doesn't want to spend huge amounts of money on electric bikes.

The idea of installing an electric drive on a bicycle suggests itself. In fact, why is it possible to use an internal combustion engine (this has been practiced for a very long time), but not to use an electric one? With the modern level of electronics, such a modernization of a bicycle should be even simpler than using other engines. In addition, this will not require coordination with the registration services of the traffic police.

For those for whom this transport is the main means of transportation (for example, for daily trips to and from work), the electrification of the “two-wheeled friend” will allow significantly save your energy and nerves. There is no need to stand idle in traffic jams that are common nowadays; the speed of an electric bicycle is decent for urban conditions, so the actual travel time is often even reduced compared to conventional ground personal or public transport.

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By constantly recharging the batteries, at home or in any accessible place, you can have a significant mileage reserve, and, with the correct calculation of the route and battery capacity, you can always be confident in your capabilities. Yes, in the end, in case of unforeseen troubles, you can get there in the usual way - on pedals.

Currently, you can, without much difficulty, purchase a ready-made bicycle with an electric drive, but its cost is quite high. Is it possible to re-equip your faithful “horse” yourself? It turns out that this is quite real, and many masters share their secrets online.

Some of them carry out a deep “upgrade” of bicycles, using completely unexpected design ideas, components and materials, often purchased at a flea market or in car dealerships. Less “advanced” ones simply purchase ready-made kits for the electrification of bicycle transport - fortunately, manufacturers offer them in a fairly wide range.

What types of transmission of rotational motion from the engine to the drive wheel exist?

Friction transmission

This type of electric drive, although found on sale, is not particularly popular. Its principle is simple. The engine is installed directly at the drive wheel, torque is transmitted directly from the stator shaft to the tire. It would seem that everything is simple and obvious. But what may be applicable for children's electric cars and bicycles is of little use in the actual use of transport.

Judge for yourself:

There are no transmission links, that is, the possibility of increasing the angular speed of the wheel through the use of gearboxes is excluded;
Extremely low efficiency;
Even a slight drop in pressure in the wheel chamber will dramatically reduce the efficiency of such a drive.
Constant friction between the engine clutch and the tire tread dramatically reduces its durability.
In conditions of wet weather, dirty roads, frost, the friction coefficient will decrease significantly, the clutch will slip, which will reduce the already low energy output of the drive.

The only advantage of this system is its ease of installation, which does not require any major modifications to the bicycle.

No, if you are planning a modification with real improvements in the performance of the bicycle, it is better to immediately abandon such a scheme.

Classic chain or belt drive

This principle is most often used by DIYers because of its visual clarity and the wide selection of necessary components from ordinary bicycles. Electric motors from household appliances (for example, a washing machine) or automotive electrical equipment are often used as a motor.

What can we say about shortcomings similar drive?

It should be immediately noted that modifying a bicycle in this way will require the owner to have sufficiently deep knowledge of mechanics and high technological skills.
Another drawback is the noise of a system with this type of transmission, but in road conditions this is unlikely to cause significant inconvenience to anyone.
The modification involves some changes in the frame design, which may reduce its strength characteristics. In any case, it is not recommended to carry out such work on bicycles with carbon or aluminum frames - only on steel ones.

But the shortcomings are brightened up by a number of benefits:

It is clear that there is a wide field for creative design ideas here. However, manufacturers have not forgotten about cyclists - there are ready-made kits for electric bicycles on sale. The most popular sets are from the Taiwanese company “Cyclone”.

Similar “constructors” are produced in different designs - using a standard bicycle chain, or with force transmission through an additional chain with one or two additional sprockets.

Systems are equipped with electric motors power from 360 to 1500 W, with a supply voltage of 24 or 36 volts. To control the operation of the drive, they are used electronic controllers, and in engines up to 500 watts they are usually built-in. The kit includes all the necessary fasteners, visual inspection and manual control of the drive.

Installing an electric drive will be a completely feasible task for any owner with “properly growing hands.”

The overall weight of the bike is quite acceptable - 3-4 kilograms, but the speeds it can reach are very impressive - 40 kilometers per hour or more.

The simplest solution is a wheel motor

For lovers of lightweight cycling, manufacturers offer another option, in which the electric motor and the wheel are structurally arranged into one unit, the so-called motor-wheel.

Advantages such a system are obvious:

When installing this drive, the bicycle does not undergo any significant modifications, and its appearance does not change significantly. The only thing is the installation of controls on the steering wheel and the battery compartment on the frame.
Installation does not require any significant knowledge and skills - with the correct selection of the wheel-motor, it is probably accessible to everyone.
The engine operation is almost silent.
If desired, the bike can easily be transformed back into a regular one.

There are, of course, a number shortcomings:

The wheel with the drive located in it is a fairly heavy structure (6 or more kilograms), increasing the total weight of the vehicle. Experienced cyclists recommend installing a reinforced front fork.
There are certain restrictions on drive power.
Exceeding the speed set by the manufacturer can have the opposite effect - the engine turns into a generator and spontaneously slows down the movement.

The kits sold are a brushless electric motor assembled in the wheel hub with a power from 200 to 1000 W.

As a rule, ready-made designs - with spokes and a wheel rim - go on sale, but for those who like to approach the matter in detail, simple engines are also sold. In this case, the selection and installation of the necessary spokes and rim falls on the owners of the vehicle. So to speak, a do-it-yourself motor-wheel.

The kit necessarily includes a controller that ensures proper operation of the drive, control mechanisms, and batteries with a charging unit.

Depending on your preferences, you can choose either a front or rear drive wheel. Some cyclists solve the problem “in one fell swoop” - they make their “car” all-wheel drive.

Wheel motors are considered the most popular among fans of electric drives. "Polariss", "Yamasaki", "Electra", "Golden motor". You can purchase them both through specialized stores and by ordering online.

Realistically assessing your need for an electric bicycle, your financial viability and technical readiness to perform manual installation, you can make a choice in favor of one model or another.

Video

Today we will talk about how to assemble or make an electric bicycle with your own hands at home. We will also learn how to convert a simple mountain bike into an electric bike using an electric wheel – photos and instructions

Even an electric bike assembled with your own hands on the basis of the simplest bicycle has a small engine that successfully pushes it forward. We can say that this is the least powerful, but still a transport. Depending on the motor power provided by the manufacturer, which ranges from 150 to 1000 W, an electric bicycle can make pedaling a little easier for unprepared riders, or even take on the entire load. True, the speed of movement of a bicycle with a motor, in comparison with a conventional one, did not increase much. The reason for this is the traffic rules that divide all vehicles into categories.

Although, of course, there are craftsmen who create homemade electric bicycles with more powerful motors, using them to reach speeds of up to 120 km/h and even climb hills without using their legs. By the way, assembling an electric bicycle with your own hands is no less popular (or even more) than factory-made ones. For those who are at least a little technically savvy, there are even special kits that include the basic components for equipping a simple city two-wheeler: the engine itself, the battery and charger for it, as well as the control controller.

Detailed video on assembling an electric bicycle from a motor-wheel kit:

A significant advantage of an electric bicycle, regardless of assembly (do-it-yourself or factory-made), is that charging its battery will not be difficult for those who have a regular power outlet nearby. Just like a mobile phone, a bicycle can be left to charge overnight; a few hours will be enough for it to be ready for “work” again in the morning. What if the battery dies on the road? It's okay, by pedaling the old fashioned way, you can get to your destination. Types of electric drive for bicycles. It doesn’t matter: you assemble the bike in a factory or do it yourself at home using ready-made kits such as the “Electric Bike Conversion Kit”. The main part that facilitates the movement of such bicycles without human effort is, of course, the electric drive. And there are several types.

The most common and recognized by numerous users for its silent operation is the built-in motor. This is the case when the motor is attached either to the front or rear, or to both wheels of the bicycle at once, without spoiling the appearance of the vehicle, but only noticeably making it heavier. A wheel with a motor is good because it has a power of 150-1000 W and does not require large expenses for installing equipment. An electric drive with a chain is noisier, but less heavy, and also practical, since many self-taught craftsmen have learned to use motors from any household electrical appliances to create their own electric bike.

The power of such an electric drive and the possibility of using a gearbox make its operation efficient and its driving quite fast. The only pity is that the cost of finished components is higher than that of the first type of motor. The friction electric drive roller of a bicycle is attractive only in its installation: there is no need to disassemble the entire structure. It is installed on top of the wheel. As the roller rotates, it transmits torque to the tire, causing the wheel to move. The friction electric drive has a large number of disadvantages in relation to other types of motors. The efficiency of such an engine is much lower than others, and the high cost and rapid wear of tires make it an unattractive option for buyers. In addition, for the system to function normally, you need to constantly monitor the pressure in the bicycle tires, and this is not entirely convenient.

The advantage of this kit is that you can easily convert a regular bicycle into a bicycle with an electric motor using these components. All you have to do is install and connect this electronic set for full operation. Let's take a closer look at the electronic kit and what is necessary for the operation of an electric bicycle:

1. The simplest thing is that your bike with different wheel diameters is taken as a basis - 20, 24, 26 or 28 inches.

2. Electric bicycle wheel - is a brushless electric motor for a DC bicycle, which is spoked into the rim. It can be installed either front or rear, or to both wheels at once - all-wheel drive. In terms of power, electric motors for a bicycle can be as follows - 250 W, 380 W, 500 W and the most powerful wheel motor is 1000w (for example, 500 W can reach speeds of up to 45 km/h, which is no small amount). This bicycle motor does not require adjustments, settings or maintenance.

3. Battery – The battery is the second most important part. Performs the function of supplying current from the battery to the electric motor. Batteries come in 12, 24, 36 and 48 volts. Although, the higher the battery power, this does not mean that the speed will increase. It is recommended to select the battery according to the voltage of the electric motor. Buy LiFePO4 batteries (lithium phosphate batteries), as they have the following advantages - cheap, reliable, durable (on average 1500 charge-discharge cycles), charge quickly (about 2-3 hours). The charger for such batteries is quite simple and in most cases resembles a charger for mobile phones.

4. Special handlebar handles (speed controller) – allow you to adjust the speed of the electric bike.

5. Controller - a block with various wires, which is responsible for the operation of the entire electronic mechanism. It is a board that is housed in an aluminum case to protect it from external influences. The best place for it is the flask holder.

6. Battery case or bag – designed for storing batteries.

7. Various wires and fuses - for the operation of the above items. You can also use regular wires from audio speakers.

Advantages of a homemade electric bike:

1. If you use a ready-made wheel motor kit, you can install it on your bike in just a few hours.

2. The price of electric motors for bicycles will be significantly lower than purchasing a ready-made, assembled electric bicycle;

3. The finished electric bike will be much heavier due to standard parts and the simplest batteries; .

4. The finished electric bicycle will have low power, since if you want to assemble the electric bicycle yourself, you will be able to select the components you are interested in individually.

We have given just a few arguments that will help you with your choice, but in order to independently assemble and invent a working mechanism, you need to understand electronics.

The main difference between an electric bicycle and a regular bicycle is the presence of a motor, batteries and a controller. In the end, I would like to conclude that the impressions from such an electric bike can only be positive

A do-it-yourself electric bike kit consists of an already assembled wheel, a controller, a gas handle, brake handles, a pedal sensor, a headlight with a lock, a horn button, and a bag for the battery.

The second part of the kit is the battery and charger.

The kits come in 12, 24, 36 and 48 volts and 250, 380, 500 and 1000 watts.
The battery is selected with the appropriate voltage. I would advise not to chase power. 380W is sufficient for flat and hilly terrain. By increasing the power, the speed will not increase significantly, but it will be better to “pull” uphill.
My personal experience is that I very rarely help with the pedals and the sprockets are always in the “maximum speed” position.

It is worth noting that in many countries there is a limit of 250W.
Why I chose 48V, I can’t say for sure now, but in May, when I was combing the Internet before purchasing, a mark was placed - take only 48V. With battery power, everything is simple - I have 10A, that’s 25 km. If you buy 20A, there will be 50 km of range and 16 kg of battery instead of 8. Decide whether it's worth carrying around the extra 4-8 kg of weight if you don't plan to travel far. I understand that power is not measured in amperes, but this is how sellers differentiate them. Not watt/hour, but voltage/amps.

Motor for a homemade electric bicycle

Wheel-motor 4. already assembled. Tire and tube not included. The wheel must be chosen according to the size of the wheels of your bicycle; for me it was number 26 - the most common size. If you bought a tube or tire, you know the size for sure.

The main thing to remember when mounting the wheel is that the cable must come out of the wheel on the left! Then it will rotate in the right direction. The second and not obvious danger is that three thick wires and several thin ones come out of the wheel. The first thing a person does after mounting a wheel is to spin it. The wheel generates electricity, a spark jumps between the power wire and one of the thin wires and that’s it, the sensor burns out, the rides are cancelled. Therefore, having taken the wheel out of the box, we immediately wrap these wires with electrical tape and hold them like that until they are connected to the controller.

You may have to slightly sharpen the seat on the fork and the axle on the wheel, this is what happened to me. A Dremel and a few cutting discs were enough to install the wheel.
Here you need to be as careful as possible; the tighter the wheel fits into place, the fewer problems there will be in the future. Don't waste too much. Owners of expensive bicycles with aluminum forks should choose a rear wheel; I read how a powerful kilowatt wheel simply broke off the whiskers on the fork during a test drive. The front fork is designed to pull up and back, while the wheel pulls forward and around. But the motor on the rear wheel puts loads on the frame no different from the pedals.

Electric bike controller

The controller is a small aluminum box 3. with a bundle of wires. There are no special problems with it. Find a convenient place on the frame and secure it. I luckily had two bolts on the lower beam simply screwed into the frame. I hung the controller on one of them, the second one didn’t match and I fixed it with a plastic strip. It is worth stocking up on them; they are an indispensable thing for fixing cables. The only remark. Due to legal speed limits in some countries, there is a lock in the controller. Most often this is a wire that just needs to be disconnected. A blocked controller will not allow you to accelerate faster than 25 km/h.

First, you need to replace the brake handles. I didn't change the front brake lever. I only replaced the rear one. Why do you need to change? There is a contact in the handle that turns off the electric motor during braking.

Secondly, you need to install the throttle handle on the left side of the steering wheel. Remove the rubber handle and cut it from the inside to the required width. Let's put everything in its place.

Thirdly, you need to install a headlight. The headlight contains an “ignition switch” and a sound signal. I didn’t connect the sound signal button, I can scream anyway. But I was very pleased with the pair of keys. The key replaces the power switch, and further turning turns on the headlight. It's comfortable. You won't be able to remove the key from the headlight without turning off the bike. The bicycle is quite heavy, and the travel on the pedals is also not so easy (after all, they are at maximum and you still need to turn the motor, which in this case becomes a generator) - it will not be so easy for a thief to jump on and ride off on your bicycle. Even just rolling it in your hands. This allows you to not “stress” too much by being distracted from the bike for a few minutes and not having to fasten it with a lock every time.

LEDs, in theory, should indicate the degree of battery discharge. This may be true for lead batteries, but it doesn’t work for LiFePO4 batteries. First, the battery is fully charged, then the red LED indicates the battery is empty. In addition, these are super-light LEDs and they are simply blinding right in your face at night, and they also interfere during the day. That's why this strip of sticky paper is there. Then I grind off the tips of the LEDs and add a drop of hot melt glue on top to get just a matte glow.

Self-assembled electric bike battery

This is a type of lithium battery. LiFePO4 is cheaper than its cell phone counterparts, does not explode, delivers high currents well, charges quickly, and has up to 1500 charge-discharge cycles before a noticeable decrease in capacity begins. Such batteries appeared only a year or two ago and are still little known on the market. The Chinese themselves assemble them from individual elements of the required voltage, power and size. In addition to the battery, the bag contains a charging balancer board. A bundle of wires goes from it to the battery itself. That is, the battery is charged in parts and the individual “banks” of elements are balanced among themselves.

Why not a regular lead acid battery? A battery similar in parameters to mine will weigh more than 20 kg. There will be fuss with the electrolyte, long charging, the number of charge-discharge cycles will not be more than a thousand, but only a hundred or two. Moreover, if I go to buy such batteries in my store, it will not cost much less. So even in terms of money I won’t benefit.

The wheel motor is a brushless DC motor. Its design does not include brushes, which makes the electric machine more reliable, and several Hall sensors are installed to replace the commutator.

The excitation winding is replaced with permanent neodymium magnets, which, today, are considered one of the most powerful permanent magnets. The rotor of the structure is made of high-quality electrical steel, which increases the efficiency of the structure. The wheel motor has a stationary rotor (attached to the bike's axis) and a rotating stator. When choosing a wheel motor, you should analyze for what purposes you need an electric bicycle, and, in accordance with this, choose a product of the required power.

Electric bicycles have two main methods of control: using pedals and a power control mechanism. As the name suggests, an assisted pedaling electric bike helps you pedal and requires some physical effort. With this control method, a (torque) sensor measures the speed or load to determine the required motor power. Everything is automated, so you don't have to think about anything - just get in the saddle and ride. Some e-bikes have multiple settings, while others may only have one power adjustment. You can customize the required pedaling assistance. With weak settings, the pedaling assistance will be barely noticeable, but this will help increase the operating time of the motor. With stronger settings, the power is more noticeable and you can reach very high speeds, since at the same time you will be assisted in pedaling by the motor at its full power.

On the other hand, the power adjustment mechanism does not require pedaling at all. Just like on a motorcycle, you control power and speed by twisting and holding the throttle. You can pedal in parallel, but this is not necessary.

Some e-bikes are pedal-only, others have power adjustment, and some have both. In general, assisted pedaling bikes have a variety of power settings from which to choose to suit your riding conditions, while electric bikes with both pedaling mechanisms have limited pedaling assist settings. On these bikes, full control is provided by the power adjustment mechanism (when needed) and pedal assist is of secondary importance - on flat terrain.

There are two different configurations for mounting the motor-wheel - front or rear.
Front-mounted wheel motor. Front-mount hub motors can be found on finished or converted bikes. If you are converting a standard bike, the easiest solution is to mount the motor at the front, as there will be no problems with the derailleur or chain. And since most e-bike conversion kits include rack-mounted batteries, using a hub motor up front balances the weight of the bike and improves handling.

Since there is a small risk of the front fork being destroyed by the electric motor, it is strongly recommended that the front wheel hub motor be used with a steel fork only. For finished bikes this is not a problem, since usually the motors are combined with steel forks and they are not as powerful.

Hub motors mounted on the rear wheel are common mainly on finished bicycles, since it is not difficult to install a motor at the rear at the factory. But converting a bicycle with a rear wheel motor is a little more difficult than in the case of a front hub motor, since problems arise with the chain, transmission and gear shifter. Plus you may be limited to a 6 or 7 speed freewheel. But the motor on the rear wheel provides more torque and is not as noticeable as on the front wheel. .

The battery is the most important factor affecting the overall cost of an electric bike. There are several different types of batteries available in different shapes and sizes. As a rule, ready-made electric bicycles are equipped with sealed lead-acid and lithium-ion batteries. But e-bike conversion kits also use some other types of batteries. Three main types of batteries and their subtypes that you need to know about when choosing an electric bicycle:

Sealed lead acid (SLA) batteries are the most affordable batteries, but they have the shortest lifespan and are the heaviest. Such batteries are well suited for beginners or cyclists with limited financial resources. If you decide to buy an e-bike conversion kit, you can install sealed lead-acid batteries first and replace them with more expensive ones later. For approximately every 12 V of voltage, the battery weight increases by 3.2 - 3.6 kg (x2 for 24 V, x3 for 36 V, x4 for 48 V). Lead-acid batteries are quite heavy. They are designed for 300 - 500 charges (1 - 2 years of operation). These batteries are very sensitive to the charging process and can be damaged if discharged more than 75%. In addition, by the end of the operational period their power decreases significantly.

Nickel metal hydride (NiMH) batteries are good batteries at an affordable price. They are smaller and lighter. They have a longer service life than lead-acid ones. Since most off-the-shelf electric bikes began using lead-acid and lithium-ion batteries, nickel-metal hydride batteries are only available in conversion kits that allow you to convert your bike into an electric bike yourself. NiMH batteries weigh approximately half as much as lead-acid batteries, and last 2 - 3 times longer - 400 - 600 charges (2 - 3 years of operation). Also, this type of battery does not lose power at the end of the operating period or before the final discharge.

Lithium-ion batteries (Li-Ion) have the longest lifespan and lightest weight, although they are the most expensive. Lithium-ion batteries are a general name for a large group of batteries. If you do not understand the types of lithium-ion batteries, you may get scammed in some stores or websites when sellers and manufacturers exaggerate their parameters. Types of lithium-ion batteries:
Lithium-cobalt batteries (LiCoO2) are used in laptops, mobile phones and are rarely used in electric bicycles. Very light, but unstable and unsafe. Subject to spontaneous combustion!

Lithium manganese batteries (LiMnO2) are the most common lithium batteries used in electric bicycles. The LiMnO2 battery is almost always called "lithium" or "lithium-ion". If no other specification is specified, then most likely it means a lithium-manganese battery. These are the most affordable lithium-ion batteries. And although they weigh significantly less than other types of batteries, they are the heaviest among lithium-ion ones. If anyone claims that they can withstand more than 1000 reloads, then do not believe them! This type of lithium-ion battery typically lasts 500 to 800 charges.

Lithium polymer (LiPo) batteries are slightly more expensive than lithium manganese batteries, but they have similar characteristics. They differ mainly only in design, since lithium-polymer ones do not have a hard metal shell, but only a soft polymer one.
Lithium phosphate batteries (LiFePo4) are the best lithium-ion batteries! They have the longest service life and the lightest weight among the available options! Lithium phosphate batteries are the most expensive, but they can withstand up to 1500 - 2000 charges and they have the most stable discharge schedule of all possible batteries, which means they do not lose power throughout the entire period of operation until they are completely discharged.

Battery voltage of a homemade electric bicycle.

As a rule, electric bicycles operate on voltages of 24, 36 and 48 V. As a rule, the higher the voltage, the higher the maximum speed, although this is not always the case (check the data sheet). Since power and speed can be influenced by the efficiency of the motor and transmission, a 24V e-bike may have the same top speed as a 36V e-bike. But the general rule is that higher voltage bikes are more efficient. fast. At 24 V the maximum speed can be 24 - 29 km/h, at 36 V - 26 - 32 km/h, at 48 V - 39 - 45 km/h.

Although these characteristics are outside the legal limits, some conversion kits can even be 72V and reach speeds in excess of 56km/h! But such high speeds can place significant stress on the bike's components. Keep in mind that even the fastest athletes travel on a bicycle at an average speed of only 27 - 29 km/h. 32 km/h seems like a very fast speed for most cyclists. Anything above this speed is unsafe and breaks the law. In addition, the higher the voltage, the more batteries are installed, which means the higher their price and weight.

Battery capacity of a homemade electric bicycle.

Batteries are rated by voltage (V) and ampere-hours (Ah). Voltage gets the most attention, but amp hours are just as important. Amp-hours measure the capacity of a battery. It is a good indicator of the number of kilometers that can be driven on a single battery charge. Although many other factors also have an impact: the weight of the cyclist, terrain, power consumption, efficiency, etc., but usually this distance depends on the battery capacity. So, on average, the average cyclist with a 10 Ah battery can travel 16 kilometers (without pedaling). And if the cyclist is pedaling, this number can be significantly higher, so most 10 Ah batteries are rated by manufacturers, based on pedaling, as being “capable of traveling up to 20 miles.”

Bicycles that offer assisted pedaling have a much higher power range. This is due to the fact that the cyclist is constantly assisting the engine and thereby reducing the current (power).

However, we believe that the powerful e-bike is the personal transport of the future and will continue to gain popularity. Having all the practical advantages and speed of a scooter, it is more versatile and passable, maneuverable, silent, environmentally friendly, and cheaper to operate. An electric bicycle can be stored at home; it does not require a garage or secure parking, like a motorcycle or scooter, which is dangerous to leave outside overnight.

The popularity of such a compact, lightweight and safe form of transport as a folding electric bicycle is growing from year to year. How to make such a design with your own hands to save on purchases?

Advantages

Experts say that to make a fashionable and durable design, all you need is a little ingenuity, buy the appropriate parts - and your faithful electric horse is ready. It has many advantages:

with such transport you can easily move around a city full of traffic jams;
it does not require a driver's license;
no need for fuel, just recharging for the electrical controller;
it helps maintain athletic shape due to the muscular strength used;
a homemade electric bicycle made with your own hands helps you to be independent of stores and market prices.

The average unit reaches speeds of up to 42 kilometers per hour, and at cruising speed it goes at 26 kilometers per hour.

The weight of the entire device will be up to 35 kilograms. To make a high-quality and reliable model from available materials, you should use the recommendations of experienced craftsmen.

We make wheeled vehicles ourselves

Where does the assembly of the entire model begin? First, we need to decide what the result should look like and what goals we want to achieve with the help of this transport. You can buy a special kit for an electric bicycle - it greatly simplifies the entire assembly work. But the most important thing that is needed is the unit itself with a thicker frame on which an electric motor can be installed.

You can find the necessary parts and components at sales, in stores for inventors, and in markets with technical goods. An advanced student can easily assemble an electric bicycle with his own hands in 30 minutes.

Main Components

Typically you need a 48-volt motor, a sturdy bike that can handle it, and some tools and mounts. As well as patience and resourcefulness, readiness for technical tests.

Additionally you will need:

special controller with programmable control;
acid batteries for the power system;
disc brake (2 pcs.) rotor type, mechanical;
moped chain;
“asterisk” with 13 and 66 teeth;
switches;
circuit breakers;
stainless steel motor mounts.

Some craftsmen prefer to assemble a folding bicycle, which in seconds can turn from a regular one into a cargo bike or fit in the trunk. The collapsible version is convenient for many reasons - reduced wheel size, ease of transportation in an elevator.

The essence of the modification is to cut the frame, to which connecting units are welded in two places. They are fixed with special bolts, screws and the procedure for assembling and disassembling the unit at home takes less than 1-2 minutes.

Engine selection

A homemade electric bicycle requires the installation of an appropriate technical superstructure that will facilitate muscular efforts. The main element of the entire structure is the engine. It is selected according to the desired voltage and current. In this case, the resulting power should be around 400 watts, then it will be possible to reach speeds of up to 30 kilometers per hour with a gearbox. The travel range can also reach 30 kilometers, depending on the battery power.

Before choosing a model, it is important to consider the balance between the voltage and capacity of the battery and the voltage and capacity of the engine. For example, when choosing a 500-watt, 12-volt motor, you need a battery with a capacity of 40 amperes per hour. The permissible capacity is calculated according to Ohm's law. At a normal level of discharge, the battery will last longer and be more reliable. To save energy, it is better to accelerate with muscle power while standing on the pedals - this will save energy by a factor of 1.2. It is better to spend the charge on more difficult areas while moving: hills and slides, dirt roads.

Resistor setting

A three-wheeled adult or two-wheeled electric bicycle equally requires the presence of throttle grips. The variable resistor option helps control the speed change and the number of engine revolutions. Having calculated the AC power, take the appropriate device with the required voltage. Opening contacts are installed on the brake handle - their position is always closed, allowing electricity to pass through the circuit. Pressing the contacts opens and closes the circuit - the engine stops or accelerates.

Typically, a standard e-bike kit contains the necessary parts for assembly. The master's task is to make sure that the engine stops when pressure is applied to the brake handle. To do this, take two aluminum pieces. One is installed on the moving parts of the brakes, the second on the stationary parts. Connecting this combination to the open circuit of the motor, which is attached to the brackets by welding, provides a functional electric brake.

Scheme development

To assemble an electric bicycle with your own hands in 30 minutes, you need a minimum of skills, but knowledge of some laws of physics is required.

For example, Ohm's law, resistance of materials or electrical conductivity of various substances. By drawing up a simple diagram in accordance with classical technical requirements, you can clearly see gaps in the design, the causes of possible problems or opportunities for further modification.

The electric bicycle circuit includes the following elements:

bicycle body;
current source;
engine;
variable resistor for introducing an open circuit;
battery.

Different schemes make it possible to improve the invention and accelerate vehicles to higher speeds using the same battery.

Choosing a controller

The main difference between a classic vehicle and an electrified one is the presence of a special control device. This is a controller for an electric bicycle, which is a box that manipulates the traction of the entire unit. If your country has a speed limit for cycling, this device will help you set the limit while riding. Most often it is 25 kilometers per hour.

The design of such a sensor does not include electric brushes.

But there is a processor that monitors the position of the wheel rim magnets. The controller allows you to optimally distribute the load on the wheels, reduce heat generation, and allow the engine to normalize the effort of moving without jerking.

Developed movement algorithms help you move evenly and at the same speed.

Operating rules

Today you can see with your own eyes quite a few vehicles assembled by craftsmen. They perform mountain climbs, dangerous stunts, and conquer gorges. But you can simply enjoy a good, reliable car that has received a second wind thanks to the engine.

It is important to follow the technology for making an electric bicycle with your own hands in 30 minutes, but you need to pay no less attention to the recommendations for the correct use of this vehicle.

You cannot constantly overstress the battery by exceeding the set speed in the engine. Also, the bike should not be placed in the sun - the battery may overheat and lose capacity by 80% of its original volume. Temperatures around 40-45 degrees are especially dangerous in hot countries.

You can assemble an electric bicycle with your own hands in 30 minutes with sufficient quality. It will last for many years if you follow safety precautions and correctly follow all recommendations.

So, we figured out how to make a homemade folding electric bike. As you can see, there is nothing complicated about this.