How to turn a regular bicycle into an electric one. How to make an electric bike from a regular bike? What controller is needed and how to set the resistor

Today we will tell you whether it is possible to make an electric bicycle in 30 minutes. The popularity of this safe, compact and lightweight type of transport is constantly growing. There is nothing complicated in the algorithm described below. We will pay special attention to the option of creating a folding structure. This product will last for many years if you follow safety precautions.

Advantages

Experts say that if you use a ready-made kit for an electric bicycle, assembly in 30 minutes is quite possible, just be smart. Such a vehicle has many advantages. It allows you to conveniently move around the city, which has a lot of traffic jams. No rights are required for such a tool.

In this case, there is also no need for fuel; only recharging the electrical controller is sufficient. This solution helps keep its owner fit, as it uses muscular strength.

It should also be noted that you can make an electric bicycle at home, with your own hands, thereby not depending on market prices and stores. The average unit can reach 42 km per hour. Weight will be about 35 kg.

We make transport

Assembling an electric bicycle in 30 minutes is a reality even for a schoolchild. But before you start assembling the model, you should decide what the result should look like and what specific tasks will be assigned to this transport. You can purchase a special kit for assembling an electric bicycle. This approach will greatly simplify all the work.

However, the most necessary element is the unit itself, which must have a thicker frame. We have to install an electric motor on it. You can find the necessary components and parts in technical markets, in special stores for inventors, and at sales.

Main Components

We'll need a 48 volt motor and a bike that can handle it. In addition, a number of fasteners and tools will be used. And also resourcefulness.

Additionally you will need:

• motor mounts, made of stainless steel;
• circuit breakers;
• switches;
• “asterisk” with 66 and 13 teeth;
• moped chain;
• rotary disc brake (2 pieces);
• acid batteries to start the power system;
• a special controller equipped with programmable control.

Next, modifications are made to the brakes and wheel fork. You can assemble an electric bicycle with your own hands in 30 minutes, but you should start with the front fork. After this we install the motor, battery, resistor. Craftsmen prefer to make a folding bicycle.

In a matter of seconds, such a vehicle can turn into a cargo version or fit in the trunk. The collapsible version can be considered more convenient in many ways, for example, ease of transportation in an elevator and reduced wheel size. The essence of the modification can be reduced to cutting the frame.

The connecting nodes should be welded to it in two places. They are secured using special bolts, screws and wing nuts. The unit disassembly procedure takes from one to two minutes.

Engine selection

If you decide to assemble an electric bicycle with your own hands in 30 minutes, you should remember that such a product requires an appropriate technical add-on. This will ease muscle effort. The engine is the main structural element. It should be selected according to the required current and voltage.

In this case, the power should be about 400 watts, in which case it will be possible to reach a speed of 30 km per hour, subject to the presence of a gearbox. The travel range is also within thirty kilometers. However, the latter indicator depends on the battery power.

Before choosing a model, you should consider the balance between battery capacity and voltage, as well as the corresponding engine performance. Let's look at this dependence with an example. If you use a 12-volt, 500-watt motor, you need a battery that has a capacity of forty amperes per hour. The permissible indicator can be calculated using Ohm's law.

If the discharge level is good, the battery can last longer. To save energy, it is advisable to accelerate with muscular force, while you need to stand on the pedals. This approach will save energy by a factor of 1.2. It is better to use up the charge while traveling on more difficult sections of the road. For example, the path may pass through a dirt road, slides and hills.

Resistor setting

To assemble an electric bicycle with your own hands in 30 minutes, you should take care of special gas handles. The variable resistor option makes it possible to control the number of engine revolutions and speed changes. It is necessary to first calculate the AC power, and then use the appropriate device with the required voltage.

Opening contacts are installed on the brake handle. Their position is always closed and allows electricity to flow through the circuit. Pressing the contacts closes and opens the circuit - the engine speeds up or stops. A standard kit usually contains the parts necessary for assembly.

The master’s task is to assemble them in such a way that the engine stops when you press the brake handle. To do this, use two aluminum pieces. We install one on the moving elements of the brakes, and the second on those that are at rest.

By welding, we connect this combination to the open circuit in the engine. For this we use brackets. This solution will provide the design with a functional electric brake.

Finishing touch

To design an electric bicycle with your own hands in 30 minutes, you will need knowledge of several laws of physics. For example, the electrical conductivity of various substances and the resistance of materials. Ohm's law will also come in handy.

With proper design, you can see in advance the gaps in the design being created, as well as determine the causes of possible problems or opportunities for subsequent modification. The structure of an electric bicycle includes the following elements: body, battery, variable resistor, motor.

REG.RU technical director Valery Studennikov tried to solve the transport problem for himself, and then turned his hobby into an interesting startup.

We present to your attention the story of the founder of Electron Bikes about how to make a powerful electric bicycle with your own hands, why speed lovers are not satisfied with existing bike models, and to what speed a seemingly ordinary bicycle can accelerate.

First acquaintance with electric bikes

I first saw electric bicycles four years ago, in 2011, at a bicycle exhibition in Moscow. Expensive, unprepossessing, very weak in characteristics, but somehow they hooked me, I felt a desire to join this interesting type of transport. A market study at that time showed that it was simply unrealistic to buy a ready-made electric bike with good characteristics at an adequate price. The market offers either very low-power and low-speed bicycles with a small battery (“weak” in all respects China or expensive, glamorous, but equally slow-moving Europe), or super-expensive monsters, whose cost from the manufacturer starts from $10,000 (Stealth Electric Bikes, Hi-Power Cycles), which also have their drawbacks (inadequately large weight due to the heavy frame and heavy motor-wheel, weak traction at the bottom due to the use of gearless motors, small power reserve).
But the persistent desire to get a silent, lightweight and at the same time powerful and playful electric bike has not disappeared anywhere. Therefore, I had to choose the only available option - to assemble the bike myself from components available on the market, as many other enthusiasts do.

First pancake

The first “lump” was an attempt to assemble a bike based on a kilowatt MagicPie wheel motor with a built-in controller, purchased complete with a 10 Ah battery for installation on the trunk. It was possible to assemble the device, but the joy from the new bicycle, which accelerated to an unprecedented 42 km/h, was short-lived - the trunk, under the weight of the battery, lived for exactly three days, breaking down on the broken roads of Samara. Handling and weight distribution with this battery arrangement were also not very encouraging. It was also hard for the rear wheel, which had already gained weight - at speed in the next pit, you could easily break the tube or even bend the rear rim.

Therefore, during the next modification, the battery was moved to the down tube of the bicycle using homemade mounts. As a result, the weight distribution turned out better, but the design looked scary and indecent. To describe such creations of crazy hands, domestic bike builders even have an established term - “martyr design”.

It was already possible to ride a bike with a more correct weight distribution quite comfortably, but it became clear that a standard 500 Wh (50 V, 10 Ah) battery for a bicycle with above-average power does not last long - you can get from point A to point on electricity B, and back only on the pedals. As a result, a large 1000 Wh battery (50 V, 20 Ah) was purchased, which seemed to fit into the front triangle of the frame, but it had to be secured with electrical tape;) It all looked like this:

The resulting monster, due to the width of the battery, did not even have pedals to rotate.

It is clear that it was impossible to leave it like that.

It was necessary to come up with something with the battery - change its spatial layout so that the pedals would not touch it, and figure out its mounting, making a reliable battery box. To complete this task, after a long search and screening out candidates, Alexander Kostyuk was brought in, an acquaintance from the VeloSamara cycling club, who was also deeply imbued with the idea of ​​designing an electric bicycle. Having many years of experience behind him in designing and building various prototypes of everything that moves, he took on the task of building a box. It was decided to make it from AMG sheet (an alloy of aluminum and magnesium) 2.5 mm thick, connected with aluminum corners. Boxing is powder coated. The bike was also equipped with a Cycle Analyst wattmeter, which allows you to measure a bunch of indicators, including energy consumption in watt-hours per kilometer. With such a device, you no longer had to worry that the battery would suddenly run out at the most inopportune moment - every ampere-hour or watt-hour spent counted. The end result was this bike:

With such a device with a capacious, conveniently and securely attached battery, one could safely ride around the city without fear that something would fall off at the most inopportune moment. And the bike already looked more decent. The bike was ready just before the winter of 2012-2013 and performed well in winter conditions, including riding in snowfalls, blizzards and frosts of minus 35 degrees.

Only forward!

After the successful completion of the construction of the first device, the idea arose to continue designing electric bikes together with Sasha. I had a certain vision of what I wanted, and Sasha had vast design experience.
We decided not to stop there also because there were simply no electric bicycles on the Russian market at that time (and still aren’t) that we ourselves would like to ride. The niche of sufficiently powerful (comparable in speed and dynamics to a scooter or motorcycle) and at the same time light and affordable electric bicycles was completely empty. And Sasha and I were not at all interested in low-power bicycles, because we, active and young, wanted to ride “with the wind”, so that the bike would have decent mileage and a reliable design for riding on harsh Russian roads and off-road.

It was decided to create a universal electric kit that would allow you to turn any modern mountain bike into an electric one. Mountain bikes were not chosen as a base by chance - they are very popular in Russia (quantitatively they constitute the main class of bicycles for adults), universal (they allow you to ride both in the city and off-road) and reliable. It is also important that the parts and assemblies of mountain bikes are standardized, which also makes it possible to standardize the electrical kit.

It was necessary to select adequate components for the bike and solve a number of engineering problems:

• Choose a motor that can produce high power and torque, while being lightweight.
• Assemble a compact and lightweight battery of sufficient capacity capable of holding large currents.
• Strengthen the rear wheel dropouts so that the high-torque engine axle does not rotate in them.
• Develop response sensors for hydraulic brakes (serial hydraulic brakes with sensors are just beginning to appear on the market and have their drawbacks), because automatic shutdown of the motor when the brakes are pressed is one of the basic standard requirements for electric bikes. And mechanical brakes are no longer suitable for safe braking at the speeds we intended to achieve.
• Consider solutions for powering the front headlight and rear light (with a signal) from the on-board voltage of the electric bicycle, providing a built-in DC-DC converter.
• Decide on suitable connectors (preferably sealed), cycling computers, wattmeters, lighting equipment and much more.

But most importantly, it was necessary to develop a universal box for the battery and controller to quickly convert a regular production bicycle into an electric one. The previously assembled metal box was not suitable for this role, since it required too much labor to manufacture and was tailored in shape and size only to a specific frame.

The final solution had to be easy to install, technologically advanced and cheap to manufacture.

Here is one of the first stages on this path, a box built in the spring of 2013:

Here is another intermediate stage:

What happened?

As a result of a year of work and experiments, truly universal and much more aesthetic boxes, electrical kits and bicycles based on them were developed:

Characteristics of these devices:

• speed - up to 63 km/h;
• power - up to 2.5 kW;
• battery capacity - up to 1 kWh;
• range - 40 km at maximum speed (63 km/h) and up to 100 km in economy mode (30 km/h).

Here is a video of a powerful electric bike moving in the “urban jungle”:

In rough terrain, the bike also does not give up:

More videos

Bicycle or motorcycle?

The bikes based on the created electric kit turned out to be really very playful, capable of fully moving in city traffic at a speed of 60 km/h. According to the new rules governing the power and speed of electric bikes, they formally do not apply either to bicycles (whose electric power is limited to 250 W and 25 km/h), or even to mopeds (whose design speed should not exceed 50 km/h), but belong to the class of motorcycles. Despite the fact that the appearance of this bike does not cause any particular suspicion - it is an ordinary-looking bicycle with a box inside the frame. And the weight of the device has not increased much; the powerful electrical kit adds only 14 kg to the bike, resulting in the weight of the finished bike being around 26 kg. An adult man can easily lift such a device up stairs and carry it over obstacles.

So it turned out to be functionally quite a moped, but in a bicycle shell. As a result, you can take advantage of both types of transport: we have a “green light” for a bicycle everywhere (pedestrian zones, sidewalks, overground and underground passages, overpasses, parks, paths and just off-road), while the speed and dynamics of a moped are available on the road / scooter (with greater maneuverability than any scooter or motorcycle), which makes a powerful electric bike in real traffic conditions the fastest urban land transport.

And although the power of our standard electric kits is already comparable to a moped, as a sport and an experiment (not a cheap one, as it turned out after calculating the cost of all components), heavy and powerful electric bicycles were assembled on the basis of specialized space frames from Qulbix:

And the Ukrainian “Chobotar frame”:

These 6-10 kW monsters are capable of reaching speeds of up to 90 km/h, while having the dynamics of a light motorcycle. And when you open the full throttle, they stand up “on the goat”. The 3 kWh battery allows you to travel 120 km at a speed of 40 km/h or 40 km at a speed of 90 km/h, so you can use this bike as a long-distance suburban transport and for driving on the highway.

What's next?

The design of Electron Bikes electric kits and e-bikes continues to continually improve. Two bicycle models will soon be ready for industrial serial production:

“Standard” (based on a regular bicycle frame): power 2.2 kW, battery capacity 1 kW*h, speed up to 63 km/h;

Electric choppers (without pedals) “Electro-classic”: power 6 kW, speed up to 85 km/h, capacity of two removable batteries up to 3 kW*h;

And "Electro-bobber".

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The latter is also equipped with a unique limited-edition titanium parallelogram fork.

A little about the design of an electric bicycle

In the end, a little about the structure and components of an electric bicycle, as well as about the technical difficulties standing in the way of the creators of a powerful bike.

Main electrical components of an electric bicycle

The “heart” or muscles of an electric bike is electric motor(more details about motors and their types below). Modern electric bicycles use brushless direct current motors (BLDC), allowing them to operate efficiently over a wide speed range with high torque. Occasionally, asynchronous motors are used as central ones. (A separate revealing material can be released about “Shkondin Engines”, about which there is so much noise on the Internet;).

The “brain” of the electric bike is controller. The controller controls the electric motor, supplying power to its windings at the right moment depending on the required rotation speed and power. The controller also controls the entire “logic” of the bike: at the input, receiving signals from the position of the gas handle, operating mode switches (you can, for example, limit speed, power in different modes, or even turn on reverse), cruise control buttons (very helpful when riding in suburban mode), signals from brake sensors (since you need to turn off the engine power when you press the brake handle or even turn on regenerative engine braking, if supported), etc.

The energy to power the heart and brain of the electric bike is stored in battery. The usual battery voltage for electric bicycles is from 36 V to 48 V. High-speed devices can be equipped with high-voltage batteries (up to 100 V).
Currently, the vast majority of electric bicycles use lithium batteries (more about their types below), which have the best energy capacity. Heavy lead batteries are used only on the cheapest devices.
The battery consists of individual battery cells connected in series/parallel.

The battery also has its own “brain” - this is the battery management system (Battery Management System or BMS). Protects the battery from overcharging, overdischarging, exceeding the permissible current, and also balances individual battery cells so that they are discharged evenly.

To display all the necessary information and accurately “calorie count” you need wattmeter, allowing you to tell exactly how much energy has been spent and how much is left. A specialized wattmeter combines the functions of a cycling computer, also counting speed, distance and derived indicators such as energy consumption per kilometer (Wh / km).

To power low-voltage consumers (headlight, taillight, horn, repeaters), it is necessary to reduce the on-board voltage to a lower one (5, 8 or 12 volts). For this purpose, highly efficient DC/DC converters are used ( DC-DC).

Difficulties of adolescence

The task of creating a powerful bike is complicated by the fact that the entire industry of components for electric bicycles is currently designed for low-power devices. The class of powerful and high-speed electric bikes, standing halfway to motorcycles, is just being formed, so the creators of such devices have to come up with something at every step.

Batteries

Commercially produced batteries for electric bicycles are usually created from cells that cannot withstand high currents. The C-rating (the ratio of the current that the battery is capable of delivering to the battery capacity, expressed in ampere-hours) of commercial batteries, usually composed of lithium-ion cells, is no more than 1, while for powerful bicycles, which we create, requires batteries with a C-rating of at least 2.5. That is, for example, with a capacity of 20 A*h, they are capable of delivering a current of 50 A for a long time. Which, with a 50-volt battery, would allow a power output of 2.5 kW - the minimum we are interested in. As a result, the batteries have to be soldered (and now welded using spot welding) independently from elements suitable for this. Searching and selecting elements that match the characteristics, testing and rejecting them is also a separate task. Now we use prismatic LiFePO4 and LiNiCo cells, which allow us to create energy-intensive and compact batteries.

Main types of lithium battery cells

• LiFePO4 (lithium iron phosphate). They can be used in frosts down to -30 degrees, a quick charge is available in 45 minutes, they have the largest number of charge-discharge cycles (1500-2000), they can deliver more power, they are fireproof and non-flammable. However, they have twice the specific capacity of lithium-ion batteries (i.e., 2 times the weight for the same capacity), and are relatively expensive (but the specific operating cost is the lowest due to the large number of cycles).
• We use them as the main solution in kits for hardtail bicycles, however, due to their dimensions, they are not suitable for installation in the front triangle of the frame of double-cross bicycles, where there is very little free space.
• Li-Ion (lithium-ion). Classic lithium batteries used primarily to power electronics. They are the lightest and most capacious, the cheapest, and have the current maximum specific capacity (Wh/kg). However, they have a narrow operating temperature range (from 0 to +40 degrees Celsius), a small number of charge-discharge cycles (300-400), and do not allow high currents to be supplied. These batteries are most often used in low-power electric bicycles, but for high-power devices they are of little use due to their low C-rating.
• LiPo (lithium polymer). High energy intensity, almost the same as that of Li-Ion elements. Allows high discharge currents, high C-rating. However, like Li-Ion, they have a smaller number of charge-discharge cycles (300-700) and a narrow temperature range: when operated below 0, they fail, and in the heat, from a short circuit or mechanical damage, they can ignite. Due to their high fire hazard, electric bicycles are only used by intrepid enthusiasts.
• LiNiCo / LiNiCoMnO2 (lithium-nickel-cobalt). Having the advantages of LiPo (high energy intensity and the ability to deliver high currents), they are free of their disadvantages: they have a wider temperature range, and, most importantly, are fireproof. As a result of their compactness, we use them in electrical kits intended for installation on double-suspension bicycles.

Motors

But the biggest problem in the task of creating a powerful and lightweight electric bike is the motors.
Serial motors are either too low-power, or heavy, or have low efficiency, or overheat, or all three at once;)

Motors used for electric bicycles can be divided into three classes, each of which has its own disadvantages when applied to powerful electric bicycles.

Gearless motor-wheels (direct-drive)

The force of the magnetic field is transmitted directly to the wheel, which is why they are called direct drive.
They are unpretentious and reliable, since they do not contain any wearing elements except bearings. Can be used as an electric brake for regenerative braking. But they have two big drawbacks.

The first is a lot of weight. For example, a motor rated at 2.5 kW will weigh on average 7 kg, and a motor rated at 6 kW will weigh as much as 12 kg. This greatly affects the weight of the finished bike. In addition, placing a heavy motor in the rear wheel shifts the center of gravity back (the bicycle becomes uncomfortable to carry, perform tricks/jump on it), and also increases the “unsprung mass” of the wheel, which has a worse effect on its survivability, increasing the requirements for rim strength , thickness of the spokes. In this regard, wheels with heavy direct drives are often spoked into motorcycle rims, because Finding bicycle rims of the required strength is difficult.

The second drawback is low efficiency when driving at low speeds. For example, when driving uphill, on mud, sand or off-road, where it is impossible to accelerate, such a motor will overheat greatly. For example, when driving up a 20% hill, a 6 kW direct drive spherical motor will operate at approximately 20% of its efficiency, and 80% will be lost to heat. In this mode, a powerful wheel motor can overheat and burn out in a couple of minutes if it is not turned off in time (usually the motor is automatically turned off based on a signal from a temperature sensor). Which is not surprising: with weak heat dissipation in the enclosed space of the motor and operation in low efficiency mode, the windings heat up at the speed of a powerful electric kettle (4.8 kW per heating in our example with a 6 kW motor). However, to make the “kettle” heat up more slowly, you can “pour water” into it - some enthusiasts solve the problem using water cooling.

Geared motor-wheels

They contain a built-in planetary gearbox, usually having a gear ratio of 5:1. They have less weight with the same power, higher efficiency “at the bottom” compared to gearless motors. However, they are mechanically less reliable (more moving mechanical parts) and do not support regenerative braking. But, most importantly, they are not mass-produced for powers greater than 1000 W.

Central motors (middrive)

Middrives, as their name suggests, are an external drive with a high-speed electric motor, usually installed in the area of ​​the carriage assembly, transmitting force through a system of chains, gears or belts. They allow you to achieve the best power-weight ratio (the higher the speed of the electric motor, the lighter it can be made with the same power). For example, aircraft model engines with a power of 6 kW can weigh only a little over a kilogram:


For comparison, direct-drive wheel motors of the same rated power (Cromotor, Crystalite, Quanshun) weigh 12 (!) kg. Also, the location of the motor closer to the central part of the bicycle gives a more correct weight distribution, allowing such bicycles to be used, including for jumps and tricks. They can work in optimal conditions even on steep slopes and deep mud.

However, the power of mass-produced central motors for electric bicycles is usually limited to 500 W. The most powerful solution currently available is a 1500 W kit from Cyclone:

More powerful solutions based on central motors are assembled by enthusiasts on their own; there are no ready-made serial offers. The creators of such powerful bikes face a number of technical challenges.

Reduction. For high-speed motors, to reduce the speed (from several thousand to 500-700), it is necessary to use a gearbox (there are no ready-made specialized gearboxes, everyone invents it themselves) or a chain/belt drive with a high gear ratio (making your own sprockets of the required diameter).
UPD: However, solutions are starting to appear.
Broadcast. For high-power engines, a standard chain from multi-speed mountain bikes is not suitable - it will simply break or wear out very quickly. You should use a wide, strong chain for single-speed BMX bicycles, a moped or minibike chain, or a high-strength belt. And this often leads to the need to manufacture non-standard gears, bushings and overrunning clutches.

Cooling. Compact high-speed motors (often model aircraft engines are used as middrives, designed for operation in conditions of very intense airflow), when used on electric bicycles, require a separate approach to cooling: forced airflow, installation of a radiator, treatment of the windings with a thermally conductive composition for better heat dissipation, etc. P.
Switching speeds. If a bicycle chain and a standard bicycle cassette are used for gear shifting, then when shifting under high load, the cassette will very quickly become unusable. Planetary bushings don’t help much either, only some of which are capable of shifting under load. A more durable option is NuVinchi CVT bushings, which allow you to smoothly change the gear ratio. Another problem is that in the urban cycle, constantly manually changing gears is inconvenient; you need to watch not only the gas handle, but also the gear shift knob, which reduces the simplicity and convenience of driving an electric bike. The solution here may be automatic planetary / variable-speed hubs, which have appeared recently. Nevertheless, in powerful (from 2 kW) bicycles with a central motor, gear shifting is often abandoned, which simplifies the design and control; fortunately, the high-speed synchronous motor with reduction allows producing high torque at any speed.

And high-speed engines, gearboxes and chain drives are noisy.

However, due to their advantages, central motors have enormous potential and will increasingly be used in high-power electric bicycles as ready-made components and solutions become available. For now, however, powerful middrives remain the preserve of individual enthusiasts or companies creating individual solutions for themselves.

Bicycle components

Bicycle components for a charged bike also experience increased loads and require careful selection.

Durable wheels

For motor-wheels, you need a reinforced rim (a regular one can wrinkle from the increased load on the wheel, high speed and “potholes” on the roads), thicker spokes. Often, a motorcycle rim is used with heavy motor wheels.

Powerful and durable brakes

To brake a heavy bicycle at high speeds, you need good hydraulic brakes with an increased disc diameter and a long pad life.
In fact, specialized brakes for high-performance electric bicycles do not exist or are just beginning to appear. Therefore, either conventional brakes are used, which have difficulty coping with the load and wear out quickly, or the most powerful brakes for downhill cycling, which are very expensive. You can also use brakes from a minibike, adapting them yourself to bicycle standards (by making adapters for attaching a brake machine, a brake disc, or even the brake disc itself).

Reinforced forks

Bicycle shock absorbers also experience increased wear when operating at high speeds with increased weight of the device. For the most powerful and heaviest e-bikes, the only choice for durability is dual crown downhill forks; however, designed to handle very large bumps, they are too soft for driving on asphalt.

* * *

Thus, the class of high-performance electric bikes requires special attention to components, many of which are too expensive or require modifications. Specialized components for bikes that fall between the bicycle, moped and motorcycle either do not exist or are just beginning to be produced. This creates certain difficulties, but also opens up room for creativity.

Transport or entertainment?

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.

However, this is not only a practical transport, it is also a great way to spend leisure time: riding a fast, silent bike over rough terrain in “enduro” mode is an endless source of adrenaline. Also, unlike a scooter or motorcycle, which is placed in the garage with the onset of cold weather, an electric bike

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 handle. 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, with this type of battery, the power does not drop 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.

It uses an electric motor that consumes 48 Volts.

The idea of ​​constructing an electric bicycle from an ordinary pedal bicycle comes to many people, but only a few actually implement it: some lack the time, others lack the experience. Very often, such an idea comes to mind when it is especially difficult to pedal, for example, going up a mountain or moving into the wind. There are many options for DIY enthusiasts: these and use as a “driving force”, i.e. motor, motor from a chainsaw, and from a washing machine, and a wheel motor, etc.

Those who are used to achieving their goals end up with an amazing and exclusive vehicle that is a pleasure to drive.

One of the options where it will be necessary to change the frame is presented for familiarization to everyone who is faced with the problem of how to make an electric bicycle with their own hands

First of all, when starting work on creating a new design for a bicycle with an electric motor, you will need to purchase: a Felt beach cruiser, chosen for its powerful frame, to which the main elements and correct shapes will be attached. You can choose another model.

The main thing is that there is a reliable frame that will allow you to secure the elements, so that the center of gravity will be as low as possible.

To make this vehicle with a motor you need to buy:

• Electric motor (in this case Briggs and Stratton).
• The controller is similar to Alltrax AX 300A.
• Throttle knob (in our case - Magura 0-5K Ohm).
• The battery is lead-based, which includes four 12V, 21Ah batteries.
• Avid Bb7 160mm disc brake.
• Chain #35.
• Two sprockets: driving and driven (with 13 and 66 teeth, respectively).
• 300 amp fuse.
• To replace the carriage, you will need a stainless steel motor support.

Operating procedure

We immediately replace the “original” fork with a shock-absorbing one. We install disc brakes, which need to be secured using bolts.

Since the purchased model of bicycle has a foot brake, i.e. braking occurs when the pedals move in the opposite direction, you will have to work hard on making a mount for installing another brake in the area of ​​the dropouts - a disc one, having previously drilled the necessary holes for their fastening using a drilling machine.

As a rear bushing, a bushing made in the form of a double front bushing with a standard fastening (six bolts) is used. The 66 tooth sprocket does not have mounting holes, so they need to be drilled and drilled in such a way that they fit the mount. It is very important that the following are on the same axis: the hub, both sprockets and the brake rotor.

The material from which the mount for the brake and the engine is cut is a steel sheet. Then the mount is attached to a stainless steel ring, welding it strictly in the center in the place where the carriage was previously located. By welding old light stands together, you can get excellent fastening of the footrests.

The ring is a structure whose width is approximately 21 centimeters and its diameter is 21 cm. Considering the size of the motor selected for installation, the gap will be approximately three centimeters. To blow air through the engine, holes are drilled in the ring. You also need to make a notch in it on the right in order to ensure free movement for the chain. A mount for the electric motor is welded inside, and also so that the footrests can be made removable.

It is also recommended to shorten the saddle holder and weld it to the frame in the area where the rear wheel is located, strengthening the structure with an additional insert. We put a rubber cap on the seat tube, then unfold the saddle clamp.

The general appearance of the new bike, due to the low-mounted saddle and powerful wheels, resembles a retro motorcycle. In the photo you can see a hole in the top tube of the frame. It is necessary for the cable that controls the rear brake.

Aluminum battery hatches are located from the battery trays on the right and left. They are secured with bolts. The controller is mounted upside down under the top tube.

Having completed the assembly, you can move on to the electrical part - connecting the wires, testing for several hours.

Specifications

Quickly, as testing has shown, the assembled structure accelerates, maximizing development speed about 80 km/h. With help RS-232 port The controller is connected serially to the cycling computer.

It’s much more pleasant to ride a bicycle, and even one you assembled with your own hands, so you shouldn’t waste time, but just get to work.

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.