An exercise bike is great for training your heart and will also help you lose weight. I propose a simple design for a home exercise machine.
1 . From a board with a section of 10x5 cm I assembled a rectangular frame of a suitable size (depending on the dimensions of the bicycle). Using self-tapping screws, I screwed vertical racks from a board with a section of 25x5 cm to its two opposite sides. I selected the height of the racks so that when installing the bicycle on them, the wheel did not touch the floor.
2 . I attached stop pipes to the rear wheel axle (I bought them at a bicycle store, but you can make them yourself), and on the racks I cut semicircular grooves along the diameter of the pipes.
3 . This stand can be installed anywhere (house, apartment, garage). And you can make good use of your free time and enjoy a bike ride without leaving home, especially in inclement weather.
Specialist consultations
Before you get on the exercise bike, you need to remember:■ Contraindications for training on the simulator are acute heart diseases, asthma, tachycardia, angina pectoris, cancer, thrombophlebitis. If you suffer from cardiovascular disease, hypertension or hypertension, be sure to consult your doctor.
■ Proper and intense training helps improve muscle definition and get rid of fat. The back muscles are also included in the work - it improves
posture. You don’t have to worry about the occurrence of radiculitis, neuralgia, or osteochondrosis.
■ Exercise on an exercise bike is good for joints and ligaments, the cardiovascular and respiratory systems. To keep your body in good shape, 20 minutes of exercise a day is enough. For body shaping and cardio training, you need to exercise for at least 40 minutes 3 times a week.
The desire to make a trainer out of a bicycle with your own hands is commendable and completely justified, since a person who decides to do something like this is a real master and his hands grow from where they need to be. And, of course, by assembling an exercise bike with your own hands, you can save a significant amount of money without spending money on a ready-made exercise bike, the cost of which starts from several thousand rubles.
Important points during assembly
For use at home, attaching a regular bicycle to a stand is the best exercise option. In many homes there is not enough space for large structures, and a stand for the rear wheel will take up no more space than a stool.
You can make an exercise bike by placing the bike on a dimensional base with shafts fixed in it. By placing only one wheel on a small base with shafts, you will not receive any load when rotating the pedals. But if you set both wheels of a bicycle in motion, then the load when rotating the pedals increases significantly. In addition, an unsecured bicycle with both wheels rotating is much more stabilized in the vertical plane than with one wheel running. And you won't need to change the location of the bike computer's sensor for it to work.
The shafts under the rear wheel of the bicycle, for transmitting rotating motion, are connected to the shaft under the front wheel through a wide belt. By putting a few more belts on the shafts, you can increase the load on such a homemade exercise bike. And do not forget that the axes on which the rollers rotate must be lubricated.
Ways to load a homemade exercise bike
Weights on wheels
A heavy flywheel instead of a bicycle wheel is the main method of loading in many models of store-bought exercise bikes, even in modern designs. Factory models are equipped with flywheels weighing 8 kg and above as standard.
If you weight the wheel yourself with quick-release weights, it will be very difficult to balance the weight around with an accuracy of up to 1 g. Otherwise, unbalanced weights on a rapidly rotating wheel can break the spokes, hit the brakes, frame or chain.
Blades on a wheel
The air load from the open blades on the drive wheel is barely noticeable, and it cannot be changed. Perhaps you can assemble a rather complex and material-intensive structure from an old bicycle with blades closed in a large drum.
The load in this bulky device can be changed by closing the through holes on the drum with a movable lid.
Permanent magnets
In terms of efficiency, attaching powerful magnets to the wheel and frame of a bicycle is the same lightly loading method as installing blades on a wheel. The first problem will be when attaching the magnetic washers to the spokes. It is easy to attach the opposing part of the magnets to the frame on a metal plate.
One more point: the most powerful permanent magnets are neodymium, such magnets are expensive, and you will have to buy at least 20 of them.
Two rollers are installed at the bottom of the wheel, one is attached to the lever at the top of the wheel. One arm of the lever is mounted to the seat tube of the bicycle, and a set of weights is suspended from the other arm. Under the weight of suspended loads or the compression force of a spring, the wheels are held by the rollers. A poorly inflated tire is crushed when rolled onto the pressure rollers, significantly absorbing kinetic energy and converting it into heat.
You can change the load using suspended weights on a lever with an upper roller or by changing the pressure in the wheel chamber. Compression springs are rarely used in the loading mechanism of a homemade exercise bike, since they do not allow the braking force to be adjusted over a wide range.
Electric generator connection
By the way, this method, which uses electromagnetic braking, is quite effective and advanced. There is a modern industrial-made exercise bike stand in which this method of loading is elegantly implemented. An interesting video showing the benefits of this exercise bike is attached below.
Demonstration of the operation of the Tacx Genius exercise bike:
Any technically literate person can come up with the idea of implementing a patented exercise bike stand with an electric generator and build their own similar exercise machine. It’s not difficult: mount a bicycle stand on a large base, secure a rubber pressure roller at the bottom, connect a car generator to the roller shaft, connect a rheostat, a fan, a tablet or laptop charger to the outputs of the electric generator. All connected electrical appliances will create the necessary load, which can be changed by disconnecting partially connected consumers.
And you don’t need to assemble an exercise bike with a belt drive, as is usually done with most homemade products with electromagnetic braking. The belt drive is noisy during operation, and therefore will interfere with listening to music or watching videos on a tablet, laptop or computer monitor.
A home-made exercise bike can be further improved and adjusted for your convenience. It’s not difficult to make such a healthy exercise machine yourself, especially since so many people have already successfully made it and, boasting, share their experience.
In modern exercise bikes, the degree of load is regulated by friction belts, which wear out during use. Readers of the magazine "Radio" are offered an exercise bike in which the braking effect is caused not by friction, but by a magnetic field. The design turns out to be compact in size and practically “eternal”, since there are no parts subject to significant wear.
Many of those who are now over 40 remember the craze for jogging, which was preferred by most fans of a healthy lifestyle. The peak of this hobby came in the 70s and 80s of the last century, when both old and young, academicians and collective farmers ran. Jogging was considered a panacea for all diseases. A particularly powerful training effect was exerted on the cardiovascular and respiratory systems, and metabolic processes sharply intensified.
However, by the beginning of the 90s, the boom in hobby had passed, and scientists and doctors were no longer so categorical in their statements about the benefits of this type of physical exercise. It has been noted that while running can have a negative impact on a person’s musculoskeletal system, in particular, the ankle and knee joints are primarily exposed to shock loads, which can ultimately lead to their diseases (pain or crunching in the knees and etc.)
All this can be avoided when exercising on an exercise bike. While retaining all the advantages of jogging, the exercise bike is completely devoid of the latter's disadvantages - the load on the joints becomes “soft” and measured. Exercise on an exercise bike can be carried out in a room or on a balcony, which, taking into account the difficult environmental situation in large cities, reduces the risk of its negative impact on human health (contaminated precipitation, wind from industrial enterprises, highways).
Being a supporter of a healthy lifestyle, the author of these lines reacted with special understanding to the speech of the President of the Russian Federation V.V. Putin. at one of the recent meetings of the State Council, dedicated to the development of mass sports, physical education and health work with the population. Unfortunately, physical education and sports today have become an expensive pleasure. The cost of most sports equipment is quite high and is unaffordable for most Russian families (for example, the price of a modern exercise bike starts from $300). To some extent, this problem can be solved by a home exercise bike, which was made taking into account the principle of accessibility for all family members. The costs of its production are low (a frame from a junk bicycle, 2-3 meters of pipe with a diameter of 0.5 inches and an electric motor from washing machines of old models such as "Volga", "Oka", etc.) The asynchronous electric motor of a washing machine is used in a somewhat unusual mode - dynamic braking.
It is known from electrical engineering literature that when a constant voltage is applied to the stator winding of an electric motor, it forms a constant magnetic field, which, interacting with the rotating rotor, causes its braking. The braking torque is mainly determined by the m.m.f. stator winding and rotor speed. Thus, by changing the constant voltage on the winding, we will change the magnitude of the braking torque and the degree of load on the athlete.
Photo of an exercise bike.
Now about the design of the exercise bike in more detail. Its appearance is shown in the photograph. From a bicycle that has become unusable, we leave only the frame with the drive sprocket and the steering wheel. From a pipe with a diameter of 0.5 inches, using a hacksaw and a welding machine, we make a stand that will be attached to the bicycle frame instead of wheels.
The design of the stand can be arbitrary; it should provide a stable position to the exercise bike.
Now about mounting the electric motor. Most older washing machine motors have two pairs of threaded holes in the back of the bearing shield cover for mounting. From strips of angle iron, a frame is welded in the upper and lower walls, with which a “grinder” is used to cut grooves for M8 bolts. These bolts will secure the electric motor to the frame, and moving it in the grooves of the frame is necessary to adjust the chain tension. A sprocket from the rear wheel of a bicycle is attached to the electric motor shaft. There are two options here: either using a lathe they grind a bushing under the shaft to which the sprocket is welded, or, if the electric motor has a ready-made pulley, they drill holes in it and the sprocket and connect them using M5 bolts. The electric motor frame is welded to the stand, ensuring that the drive sprocket, driven sprocket and chain are in the same plane. The mechanical part is ready.
Now the electrical part. To change the physical load on the trainee, an adjustable DC source is needed.
Appearance of the current source.
It must supply a voltage of up to 42 V to the load at a current of 2.5 A.
Power supply diagram.
The conclusions of the stator winding of the electric motor are in accordance with Fig. 2a, b, c.
Circuit diagram for switching on electric motor windings during dynamic braking.
connected to a current source. The exercise bike is ready for use.
Some specific tips.
1. If the exercise bike will be used as a recreational tool, it is quite enough to use single-phase electric motors with a power of up to 200 W (washing machines, electric pumps for irrigation, etc.). When the voltage changes from 24 to 42 V (which meets safety requirements), they create a braking torque on the shaft sufficient for training both children and adults. The power dissipated on the stator windings in the form of heat does not cause excessive overheating of the motor. If the exercise bike is used for sports purposes, you will have to choose a more powerful electric motor and a DC power source. The load also depends on the ratio of the diameters of the drive and driven sprockets.
2. When using 3-phase asynchronous electric motors, they must be subjected to preliminary testing. According to the author's observation, it is inappropriate to use some types of electric motors. At low rotor rotation speeds, they develop a significant braking torque (it is difficult to move the pedals), and at high speeds they experience “sinks” (the braking effect decreases sharply). This is explained by the design feature of some types of squirrel-cage rotors.
3. A direct current source is better suited with step adjustment than with smooth adjustment, as this allows you to accurately dose the degree of load and, accordingly, note the increased training effect. The corresponding divisions are marked with paint on the adjustment handle and the front panel of the source.
4. According to safety requirements, step-down autotransformers cannot be used in the current source, since all electrical equipment and metal parts of the structure will be under a life-threatening potential of 220V. The use of partially failed electric motors (with one burnt winding or with interturn short circuits) is also undesirable, since the metal structures of the exercise bike may pass through the body of the electric motor under a voltage of 42 V, and when you touch them with sweaty parts of the body, unpleasant tingling sensations will be felt.
Literature:
1. Ivanov A.A. Handbook of Electrical Engineering. 5th ed., revised. and additional - K.: Higher School, 1984.
2. Sports medicine: Textbook for physical instructors. culture - Ed. V.L. Karpman - M.: Physical culture and sport, 1980.
http://cm001.narod.ru/index/publik/trenager.html
These are regular exercise bikes. How much power can they generate if you add a generator?
A new gym opened in Sacramento, California this month. Its difference from ordinary gyms is that all exercise bikes installed in the premises are equipped with electricity generators. According to the company's management, the electricity generated by customers will not only help recoup the cost of purchasing exercise equipment, but will also reduce carbon dioxide emissions into the atmosphere. The very idea that pedaling will help nature, according to the management of the hall, can contribute to more effective training for visitors.
Sacramento Eco Fitness estimates that in just one year, patrons will save the gym about $26,000, which will cover the cost of 15 eco-trainers purchased previously. It all sounds simply fabulous, but isn’t it all fantasy? According to one of the network users, who came across the calculations of the hall’s management, the calculations really do not correspond to reality.
Moreover, the calculations themselves were carried out back in 2011, so there was no need to perform all the calculations again. Then engineer Tom Gibson estimated the power of the “human power plant” at 50-150 W per hour. This is unlikely to be enough to power the hall and save as much as $26,000 in just one year. A number of netizens who participated in the discussion of the idea of an “eco-hall” said that all this was pure marketing, not savings. More or less realistic calculations show that gym users need to sweat on exercise machines for decades in order to recoup the company’s expenses for purchasing eco-exercise machines.
Indeed, the other day the founder of Eco Fitness explained that the idea is not at all to save a lot of money. “We want our clients to be proud of their workout every time they start exercising,” he said.
By the way, the exercise equipment installed in the gym is produced by SportsArt, which was founded in 1978 in Taiwan. ECO-POWR SportsArt exercise machines generate current with a voltage of 120 V. The system is equipped with a converter that converts the generator's direct current into alternating current with a frequency of 60 Hz. The current is supplied to the premises' power grid, which allows the generated energy to be used.
But if you think about who is making the most profit from the idea of creating exercise bikes that generate electricity, it becomes clear that the main “beneficiary” is the manufacturer, SportsArt. The cost of systems supplied by the company ranges from $2,795 to $7,395, which is significantly higher than the cost of conventional simulators. SportsArt ECO-POWR exercise bikes are also equipped with an application for mobile devices that allows you to calculate the amount of energy generated by the system.
The management of the gym recently announced the price of a monthly subscription. It's $80 a month, which is cheaper than luxury gyms but twice as much as regular gyms in the area. This, as far as can be understood, will help the hall to quickly return the funds spent. And the clients of the hall will be people who are concerned about environmental problems and who will decide, albeit at the cost of a higher subscription cost, to help nature (although in this case it is not entirely clear how generating a small amount of energy can have a positive impact on the environment). All this looks more like “green” marketing, which is becoming more and more popular, than a real intention to somehow reduce the anthropogenic load on nature.
Of course, the hall will receive some amount of energy thanks to its visitors. So, 15 simulators will work 3 times a day for 45 minutes. This will provide between 400 and 800 watts of energy during each cycle. According to the management of the hall, this amount of energy is enough to ensure the functioning of a coffee machine, two TVs and two laptops.
The owner of the hall also says that the premises uses almost exclusively sunlight for lighting during daylight hours, rather than lighting using electricity. In the future, they plan to equip the building where the hall is located with solar panels, which will increase electricity generation and reduce the load on the power grid.
Regardless, this is still a stark departure from the original claim of saving thousands of dollars on energy consumption. Greg Cramer, an engineer at Ohio University, says the energy output of systems like the machines mentioned above is extremely low. “If you want to save energy and work out physically, take a regular bike and ride it to work and school - the physical activity will be significant and energy use will be minimal. This is real savings.” It will probably be difficult to disagree with Kremer’s opinion.
At the same time, “green marketing” is now flourishing, and this will have to be tolerated for a very long time.
The desire to make a trainer out of a bicycle with your own hands is commendable and completely justified, since a person who decides to do something like this is a real master and his hands grow from where they need to be. And, of course, by assembling an exercise bike with your own hands, you can save a significant amount of money without spending money on a ready-made exercise bike, the cost of which starts from several thousand rubles.
Important points during assembly
- The exercise bike should be as stable as possible. To prevent a bicycle mounted on supports from tipping over, you need to assemble a large base. If you plan to build a small base, then it should be heavy.
- A load for an exercise bike is a must. It is useless to spin a suspended wheel without making an effort, in this way: you will not strengthen your muscles and will not train endurance.
- When you stop pedaling, the driven wheel should rotate. There is no need to create too high a load on the exercise bike, which will cause the wheel to lock. If you apply too much force to accelerate, you will overload your knee joints.
- The saddle should be comfortable. To improve your health, you will need to sit on an exercise bike for more than an hour, which will be inconvenient to do on some old unnecessary saddle.
- It is necessary to organize measurements of the distance covered, training time, and speed of movement. Most models of cycling computers take readings through a wire from a sensor mounted on the front fork. The wire is not long enough to mount the sensor on the frame near the rear wheel. The easiest way to solve this problem is to buy a more expensive cycling computer with a wireless sensor.
For use at home, attaching a regular bicycle to a stand is the best exercise option. In many homes there is not enough space for large structures, and a stand for the rear wheel will take up no more space than a stool.
You can make an exercise bike by placing the bike on a dimensional base with shafts fixed in it. By placing only one wheel on a small base with shafts, you will not receive any load when rotating the pedals. But if you set both wheels of a bicycle in motion, then the load when rotating the pedals increases significantly. In addition, an unsecured bicycle with both wheels rotating is much more stabilized in the vertical plane than with one wheel running. And you won't need to change the location of the bike computer's sensor for it to work.
The shafts under the rear wheel of the bicycle, for transmitting rotating motion, are connected to the shaft under the front wheel through a wide belt. By putting a few more belts on the shafts, you can increase the load on such a homemade exercise bike. And do not forget that the axes on which the rollers rotate must be lubricated.
Ways to load a homemade exercise bike
Weights on wheels
A heavy flywheel instead of a bicycle wheel is the main method of loading in many models of store-bought exercise bikes, even in modern designs. Factory models are equipped with flywheels weighing 8 kg and above as standard.
If you weight the wheel yourself with quick-release weights, it will be very difficult to balance the weight around with an accuracy of up to 1 g. Otherwise, unbalanced weights on a rapidly rotating wheel can break the spokes, hit the brakes, frame or chain.
Blades on a wheel
The air load from the open blades on the drive wheel is barely noticeable, and it cannot be changed. Perhaps you can assemble a rather complex and material-intensive structure from an old bicycle with blades closed in a large drum.
The load in this bulky device can be changed by closing the through holes on the drum with a movable lid.
Permanent magnets
In terms of efficiency, attaching powerful magnets to the wheel and frame of a bicycle is the same lightly loading method as installing blades on a wheel. The first problem will be when attaching the magnetic washers to the spokes. It is easy to attach the opposing part of the magnets to the frame on a metal plate.
One more point: the most powerful permanent magnets are neodymium, such magnets are expensive, and you will have to buy at least 20 of them.
Two rollers are installed at the bottom of the wheel, one is attached to the lever at the top of the wheel. One arm of the lever is mounted to the seat tube of the bicycle, and a set of weights is suspended from the other arm. Under the weight of suspended loads or the compression force of a spring, the wheels are held by the rollers. A poorly inflated tire is crushed when rolled onto the pressure rollers, significantly absorbing kinetic energy and converting it into heat.
You can change the load using suspended weights on a lever with an upper roller or by changing the pressure in the wheel chamber. Compression springs are rarely used in the loading mechanism of a homemade exercise bike, since they do not allow the braking force to be adjusted over a wide range.
Electric generator connection
By the way, this method, which uses electromagnetic braking, is quite effective and advanced. There is a modern industrial-made exercise bike stand in which this method of loading is elegantly implemented. An interesting video showing the benefits of this exercise bike is attached below.
Demonstration of the operation of the Tacx Genius exercise bike:
Any technically literate person can come up with the idea of implementing a patented exercise bike stand with an electric generator and build their own similar exercise machine. It’s not difficult: mount a bicycle stand on a large base, secure a rubber pressure roller at the bottom, connect a car generator to the roller shaft, connect a rheostat, a fan, a tablet or laptop charger to the outputs of the electric generator. All connected electrical appliances will create the necessary load, which can be changed by disconnecting partially connected consumers.
And you don’t need to assemble an exercise bike with, as is usually done with most homemade products with electromagnetic braking. The belt drive is noisy during operation, and therefore will interfere with listening to music or watching videos on a tablet, laptop or computer monitor.
A home-made exercise bike can be further improved and adjusted for your convenience. It’s not difficult to make such a healthy exercise machine yourself, especially since so many people have already successfully made it and, boasting, share their experience.