In order to make a drive star, it is not at all necessary to have a CNC or other special equipment.

It happens that it is not always possible to find and buy a star with the required number of teeth for a bicycle, moped or motorcycle. I suggest a simple and affordable way self-production of the desired star.

The technology is simple - in the Sprocket program

Download file:
(Downloads: 2073) .zip

It is necessary to make a star with the required number of teeth for a certain chain, the program is simple and does not require special knowledge. Open the downloaded archive with the program, which, in addition to the program, has instructions on how to use it.

The chain parameters indicated in the photo with a red arrow can be taken from this site, and for those who do not understand how to do this, see the manufacture of a star from beginning to end in the video.

After the star has been printed, the sheets must be connected together along a line and glued to the metal of the desired thickness. I made a star for a moped chain, and took 5.5 mm metal.

I cut off the excess metal so that it does not interfere.

In order for all the teeth to be cut equally, I fix the star and the grinder on the same rail, and the angle at which I need to cut I look at the factory star with any number of teeth.

The grinder is hinged, which allows it to be raised and lowered. After cutting on one side, I turn the star to the other side and also cut off the excess.

After that, we need to trim the height of the teeth, which I measure according to the factory sprocket, for this I fix the grinder.

After all the teeth are aligned in height, I slightly trim them on the grinder.

In fact, you can make absolutely anything out of bicycle parts. It is not always appropriate, it is not always practical, the result does not always look great, but if you have free time and materials, everything is really possible.

Let's look at the main categories of such crafts:

Art;

Disposal;

• Desire to surprise;

  Urgency;

In our article, we examined various categories, and also wrote the approximate composition of the parts that will be required to reproduce a particular idea.

Which of the ideas belongs to which category, we are sure you will guess.

Chandelier

What details are required:

• Ratchet;

  Wiring.

It is difficult to call this example a craft, it looks more like art. The chandelier diameter is 48 inches. You can read more at the link.

Table lamp

What details are required:

• Wiring.

One of the many options for table lamps made from unnecessary bicycle parts. We liked this one more than others.

Table

What details are required:

Spoked rim;

Rims without spokes;

Bicycle wheel tables are perhaps the most organic looking furniture in this article.

Armchair

What details are required:

Spoked rim;

Rims without spokes;

Such a chair looks quite comfortable and sturdy. Not sure if it is worth reproducing the idea with old rusted rims and burst cameras - it may not turn out so aesthetically.

Shop

What details are required:

To manufacture the bench, you will need the same set of parts as for the chair in the example above: rims, cameras and some stars.

Slicks are probably more suitable for a shop than embossed tires.

Chair

What details are required:

• Flask holder.

The situation when you can not think about the geometry of the frame and even the so-called "sofas", that is, soft imposing saddles, are welcome. Such a chair is quite simple to make, but at the same time it will definitely not leave anyone indifferent.

A shelf

What details are required:

We are sure that for such a shelf, some camera defects are quite acceptable and will not affect the performance. The idea looks extremely simple to implement.

What details are required:

• Wood.

Very nice trophies from Andres Scheiger (his site). The idea is quite simple: from a handlebar, a saddle and a small piece of wood, you can make a holder for a bicycle or other items.

The color, type and shape of the handlebars or saddles are almost irrelevant.

Mirror

What details are required:

Of course, a very old bent wheel with a worn tire is not very suitable for a bathroom mirror, but for a garage or hallway it is. For the bedroom and living room, do not regret to write off the wheel a little ahead of time and make a nice piece of furniture out of it.

Clock

What details are required:

Stars (optional);

Clock filling.

As we wrote in one neighboring article, wheels are one of the most important parts of a bicycle. And outside of the bike, they can do a lot of good: in addition to furniture, mirrors, shelves and much more, they can be very stylish watches.

In fact, almost any round (and not only round) part is suitable for a watch: crafts from stars and cassettes are very popular.

Fence

What details are required:

Most likely, such a fence will give you away the former owner of a bicycle workshop, otherwise where did you get so many unnecessary bicycles from?

As for how exactly to make a fence from a bicycle, there are no exact recommendations - as you can see in the above examples, you can turn on your imagination to the fullest and you will succeed.

Decorations

What details are required:

Wire;

The main thing in jewelry is to maintain balance and not go into excessive brutality.

Most often, chain links are used to create jewelry. On sites like Etsy, you can easily find many craftsmen focusing on jewelry like this.

And if you want exactly the same as in the picture, then they are in our store at a very affordable price.

Bicycle parking

The world of bicycles has its own reincarnation - after a while, old bicycles may again find themselves in their familiar world. For example, in the form of bike racks made from old bike frames.

Backpacks and bags

Not really handmade, but fits perfectly into our review. Vaho is a Barcelona-based company that manufactures backpacks and bags from old tires. On their website, they tell and show how they came to this and what comes out of it.

Old cameras not only make bags and backpacks, but also purses and travel bags. Another example of intelligent recycling from Australians.

We hope we managed to inspire you, and the next time you buy a gift for a friend or choose furniture for your home, you will think about the fact that you can do this with your own hands from unnecessary parts of the bike.

The main thing in this business is a little skill and a sense of taste: we have already seen enough of swans from car tires in the yards :)

How to make homemade bike sprocket block... A road bike is simple and reliable. It has a reliable foot brake, which is important when driving off-road, but there is no gear change, as, for example, in multi-speed bicycles of the "Tourist" type, so necessary when driving over rough (with hills and ravines) terrain.

However, the "Tourist" has only a handbrake, which, in my opinion, has neither smoothness, nor reliability, nor wear resistance, and it costs much more. Is it possible to combine the advantages of both types of bicycles? It turns out, if you think about it, it is partially possible by installing on the road instead of the standard driven sprocket block of three coaxial sprockets rigidly fastened (welded) through spacer wire rings.

First (small) star with 18 teeth, standard. It is hardened, therefore, for subsequent welding, it must be released into the block, that is, it must be heated over a fire (in a fire or over a gas burner) until it is red and cooled in air. The second and third sprockets, respectively with the number of teeth 24 and 28, are homemade. They are made of 2.3 mm thick sheet steel using the following technology. A circle is drawn on a small sheet of Whatman paper with a compass (for the second sprocket with a diameter of 97 mm).

Then the drawing paper is laid on soft cardboard (or several layers of newspapers). The part is placed on the sheet bicycle chain(24 links) so that the centers of the axes of its links are located approximately on the drawn circle, and the distance between the axes of the first and last links was equal to the pitch of the chain - 12.7 mm.

This part of the chain is neatly covered with a piece of plywood sheet and through it the hand is pressed against the Whatman paper. The prints of the axes will remain on the paper. Then this print is glued to the steel sheet and through it on the metal, in the middle of the printed circles from the axes, the centers are punched and 24 holes with a diameter of 8.5 mm are drilled.

Next, a sprocket blank is cut out of the steel sheet with a chisel or hacksaw. It remains only to mark according to the template, carefully grind each of its teeth on an emery and a file, and also make a central hole with a diameter of 51 mm. The third sprocket was made in the same way, only the diameter of the circle on the Whatman paper was 112 mm and 28 chain links were laid on it. In place of this asterisk, you can install a ready-made one from the old children's bike- it has the same number of teeth with the same pitch. Just before welding, it also needs to be released.

Two ring spacers with an inner diameter of 52 mm are bent from 6 mm steel wire. Before connecting the sprockets into a single block, for the convenience and reliability of welding them with rings, several technological holes with a diameter of 12 mm were drilled in homemade sprockets. After that, ensuring the coaxiality of the sprockets to prevent runout of the gear rims, the rings and sprockets are sequentially welded to each other by points evenly distributed around the circumference.

The produced block of sprockets is seated on the outer part of the driving cone of the rear bicycle hub and the standard (smaller) sprocket is welded to it in a circle with a reliable continuous seam. It would be possible to simply fix the block with a "native" spring ring, as usual, but there is no guarantee that the thermally released splines of the small sprocket will withstand the increased loads. For welding work, the drive cone is freed from the bearing and rollers and thermally released in the same way asterisk... Re-hardening of the part, as shown by the operation, can be omitted.

The axle is long enough to secure the drive wheel with the sprocket to the rear fork of the bike. But no matter how hard I tried, I could not design a simple and reliable home-made gearshift mechanism. Therefore, I installed a standard mechanism from an old "Tourist" bicycle on my road-builder, rigidly fixing it with an M10 bolt right in the frame hole.

The gear lever is located under the seat. For those who do not have such a speed switch, I advise you to prepare two sections of the chain with locks at both ends: the first with five links, the second with nine. Then, before the next trip, while still at home, you can lengthen (or shorten) the chain and put it on the desired sprocket, depending on the intended nature of the track, the speed of movement and your physical form.

For example, if you have to travel light on a highway, then a smaller sprocket and a shortened chain (without inserts) are selected. When it is necessary to overcome the path along a country road, and even with a load, a long segment is inserted into the chain - for a larger sprocket.

Sprocket block on the driving cone of the rear hub of a road bike: 1 - small sprocket (z = 18, t = 12.7, from a road bike); 2 - intermediate sprocket (z = 24, steel, sheet s2,3); 3 - large sprocket (z = 28, steel, sheet s2,3); 4 - annular spacer inserts (steel, wire with a diameter of 6); 5 - bushing leading cone; 6.12 - anthers; 7 - tip of the rear fork of the bicycle; 8 - axis; 9 - nut; 10 - washers; 11 - fixed cone; 13 - sleeve body; 14 - cup; 15 - leading roller; 16 - bearings

Making an asterisk

Making an impression: 1 - drive chain; 2 - Whatman sheet

Welding of spacer inserts with an asterisk through the technological holes: 1 - an asterisk; 2 - distance insert

In 1892, Professor V. Prusakov suggested using an ellipse instead of a round driving sprocket on a bicycle. He decided to place the cranks along the minor axis of the ellipse, which made it possible to more efficiently use the cyclist's forces. Experiments have shown that even an inexperienced cyclist on a car with an elliptical sprocket spends about 30% less energy than on a bicycle moving at the same speed with a round

an asterisk. And according to American engineers, the use of an oval gear increases the average speed of a cyclist by about 14%.

But, despite all this, the non-circular asterisk did not receive wide distribution either in our country or abroad: the bicycle industry turned out to be not ready for the production of unconventional chain drive elements.

However, calculating and making an elliptical sprocket is not so difficult on your own. It is only necessary to take into account that its efficiency depends on the ratio of the large and small axes of the ellipse: the larger it is, the more advantageous it is to use it. Considering this and the design features of the bicycle, they determine the maximum size of the major axis and the minimum size of the minor axis of the sprocket. Then it is necessary

where 12.7 is the pitch of the bicycle chain, n is the number of teeth of the elliptical sprocket (selected by the same method as for the chain drive with round sprockets). The length of the ellipse is calculated by the formula:

where a is the major axis of the ellipse, b is the minor axis of the ellipse. Having chosen the size of one of the axes of the ellipse, we find the value of the other axis of the ellipse. It must be such that it matches L ** up to the second decimal place. \ "An ellipse of the roller centers is constructed on the sheet metal blank from which the sprocket will be made according to the following formulas:

where a is the major axis of the ellipse, b is the minor axis of the ellipse; x and y - Coordinates of the point relative to the center of the ellipse; a = 0 °, 10 °, 20 ° …… 360 "

Further, this closed curved line is divided using a compass into n equal parts with a step of 12.7 mm. Now it will be no more difficult to cut an ellipse star out of metal than a round one. Studies have shown that the effectiveness of an elliptical sprocket increases if the minor axis of the ellipse "lags" from the connecting rod by 10 ° ... 25 °. For sports and sports-tourism bicycles of the Kharkov Bicycle Plant, an elliptical sprocket with 46 teeth and axle dimensions a = 110.18 mm, b = 73.981 mm with a / b = 1.49 ratio was calculated and manufactured. The lag of the minor axis of the ellipse from the connecting rod is 15 °. All other dimensions of the asterisk are shown in the drawing.

Now comes the fun part!

One of my readers made an asterisk from the drawings in this article:

Here's what he writes:

Read the operational properties and manufacturing principle here ... On my own behalf, I will say that the effect simply shocked me, I did not even imagine this. For example, on a forward with a 28-34 gear (front-rear sprocket) in a very steep and long mountain I drove in and wanted to fall and not get up, my tongue on my shoulder, my legs fall off. On this lisapeda, after installing elliptical stars with a gear of 32-28, I drove up the same mountain and even my breathing did not go astray, my legs felt much less load. Moreover, the speed of movement up this mountain on the forward is 6-6.5 km / h, and on this 7.5-8 km / h !!! And in a straight line on the asphalt the speed of movement increased.

Sprockets - transmission units for the implementation of chain transmission of forces from the cyclist's legs to rear wheel... Bicycle sprockets play a paramount role - without them, it simply will not go. Single speed models are supplied with a pair of leading and driven stars. Bicycles with multistage transmissions are equipped with speed kits at the front (system) and at the rear with a ratchet or cassette.

The number and size of the sprockets determine the bike's flexibility in various road conditions. Thanks to the correct gear ratio, you can significantly reduce the energy consumption for the trip and move at a comfortable speed. The durability of the parts depends on the quality of the material, the riding style and the quality of service - with proper care, even the "initial" stars will ride longer than professional, but neglected ones.

Gear ratio of leading and driven stars

Stars on speed bikes located on the right connecting rod (leading) and the rear wheel hub (driven). Through the chain, forces are transmitted from the front gears to the rear. It is interesting that the rear wheel, on the contrary, is the driving one, and the front wheel is the driven one.

Gear ratio is the difference between the dimensions and the number of teeth on the stars. This parameter directly affects the travel speed and transmission power. A high gear ratio is provided by a large drive and small driven gears, a low gear ratio, on the contrary, by a small front sprocket and a large rear sprocket. Accordingly, the gears on the classic transmission in the first case are 3 x 8, and in the second 1 x 1.

The larger the chainring, the higher the speed. For example, there are 44 teeth on the front for the chain engagement, and on the back there are 11 teeth. For one revolution of the pedals, the rear gear will make 4 revolutions. If we take gear 22 to 11, then only 2 wheel revolutions will be made here per pedal rotation. In low gears, the opposite situation is observed: in front of the chain stands on a 22-gear gear, and at the back on 32. The gear ratio is less than 1, that is, in 1 pedal revolution the wheels do not have time to turn completely.

High gears are designed for fast travel on a flat road. On hills, in headwinds and in poor road conditions, lower gears are used - the speed of the bike is lower, but more power and less energy consumption. Medium star ratios such as 2 x 5 and 2 x 6 are often used.

Each star in the system has its own range on the cassette. It can "float", that is, the same reverse gear refers to two stars of the system at once, but, in principle, the pattern is as follows:

Scheme of the optimal gear ratio for different modes ride

• collapsible on a single drum with separators;
• on a spider;
• on blocks (several spiders);
• Open-Glide;
• X-Dome.

The first type of cassette is the simplest - all the stars are installed on a single spline drum. They are separated from each other by partitions - spacers. The disadvantage is the constant load on the drum. But the indisputable advantage is that they are easy to disassemble and change one asterisk. They are easy to clean, but the components are more likely to get dirty.

Spider is a light version of a collapsible cassette. The load on the drum is not so big - here it does not come from each star, but only from the spline mount of the spider. These cassettes are lighter and less likely to get dirty.

The multi-spider design includes multiple pairs plus small stars individually attached to the drum. The model is very convenient because the new block is easy to pick up and, unlike a collapsible analogue, you don't have to fiddle with spacers for a long time and lay out the entire cassette. The development of this thing belongs to the Japanese parts manufacturer Shimano.

The Open Glide is a one-piece set that fits onto the largest gear. Unpretentious model: thanks to high-quality material, less wear and tear, long service life, low weight. However, cleaning a heavily soiled cassette is problematic.

SRAM X-Dome One-Piece Gear Set

The X-Dome system is represented by a similar design. Here, both the big and the small stars are in contact with the drum. A solid-milled block of 7-8 stars is mounted on them. Both Open-Glide and X-Dome are owned by SRAM.

How to clean and lubricate sprockets

Rubbing mechanisms require periodic lubrication and cleaning from dirt. This will improve ride quality and extend the life of the transmission. Chain guards are often included with the classic single-speed models. It is recommended to leave it. It also protects the chainring from excess dirt.

Already after a few rides through forests, cross-country and off-road Mountain bike overgrown with dirt. And if it is clearly visible on wheels and frame, then in mechanisms it is not always. Therefore, more often you need to inspect your two-wheeled horse and take action in time.

Cleaning the bike cassette:
1. Release the rim brake (remove the caliper on the disc brake), remove the rear wheel.

2. Inspect for dirt. If everything is very bad, you will have to remove and disassemble the tape. For light dirt, it can be cleaned directly on the wheel.

3. For cleaning it is better to use special narrow brushes. They allow you to crawl into the deep gaps between the gears and find a lot of interesting things there. And it is much more convenient than getting into the gaps with a rag.

4. You can clean the teeth with an old toothbrush or wipe off the abrasive with a soft cloth.

5. Then wipe the surfaces with kerosene, allow to dry and apply grease to the teeth and pits. It is recommended to clean and lubricate the chain at the same time as the cassette. Only in this way will the desired result be achieved.

Cleaning the system is done by analogy. Everything is simpler here: you do not need to remove the wheel, only a few stars. True, you need to work carefully so as not to damage or upset the switch.

Sprockets are the most important components of the transmission, without which movement is impossible in principle. Correct selection gears, periodic cleaning and timely replacement of worn out components will avoid unpleasant surprises on the road, and, indeed, it will be high-speed, and not go in only one gear.