Rear sprocket, ratchet and cassette. Rear sprocket for Torpedo bushings
Torpedo hubs are installed on most modern single-speed bicycles. road, teenage, folding and children. Such bushings are equipped with one driven sprocket, which is attached by means of a splined connection to the driving cone. First, a boot is put on the driving cone, then the star itself and then all this is clamped by a support ring in special grooves of the driving cone.
Attaching the rear sprocket to the hub of a single speed bike
Bicycle rear wheel ratchet
The bike ratchet is part of the bike’s drivetrain and consists of a set of sprockets combined with a freewheel hub. This type of chainring appeared earlier than cassettes and is considered obsolete. These days, cassettes are mostly found on entry-level bicycles that are not subject to heavy loads. The downside of this design is incompatibility with the hollow eccentric axle. Due to the fact that the freewheel bearings are outside the bushing, part of this axle may burst under heavy loads. That is why almost all ratchet bushings have an axle for nuts. In addition, ratchets can contain a maximum of seven stars, very rarely eight, while cassettes are also available with 11 stars. The main advantage of the ratchet is its affordable price, which has made it popular among non-professional bicycles.
Attaching the Ratchet to the Bicycle Rear Wheel Hub.
The ratchet of the rear wheel of the bicycle is attached to the hub using a threaded connection, but the ratchet can only be removed using a special puller (see the figure below).
The ratchet bushing device is quite simple and is based on a ratchet mechanism, therefore it is often called a ratchet. On the axis of the sleeve there are pawls, which are fixed with a special ring. The axle itself attaches directly to the rear hub of the bike. On the inside of the body there are special toothed protrusions. There is a set of stars on the body. The axle and the housing interact with each other through pawls and bearings. When the cyclist presses down on the pedals and transfers the force to the ratchet stars, the pawls rest on the lugs and twist the bicycle wheel hub. As soon as the ratchet stars stop, and with them the body of the ratchet bushing stops, the dogs begin to slip over the lugs. The wheel spins further freely from the rear sprockets and, accordingly, the pedals. When free running, you can hear characteristic clicks, these are the dogs beating against the ledge on the ratchet body.
Ratchet bushing details
Bicycle rear wheel cassette
A cassette is a part of a bicycle, consisting of a set of stars fixed to each other. The cassette is put on the free wheel of the rear bushing using a splined connection and secured with a special nut. The difference between cassette and ratchet is that the freewheel hub (drum or nut) at the ratchet is integrated into it, while at the cassette it is located directly in the rear hub of the bike.
Cassette and sleeve with drum for cassette
It makes no sense to consider the device and the principle of operation of the drum of the cassette sleeve, since it is similar to the freewheeling sleeve of the ratchet.
Classification of cassettes by the number of stars
Cassettes can contain seven to eleven stars. over, the bushings are most often produced for 8.9 and 10 stars, since with a smaller number of stars, a ratchet is usually used. Eleven star cassettes are currently only available for the Campagnolo system and are only compatible with similar hubs.
Materials for making cassettes
The most ideal option is steel with special coatings. Such cassettes are more durable, but also heavier than titanium and aluminum. The more expensive the steel cassette is, the longer it will last.
Aluminum cassettes are very lightweight but wear out very quickly. The titanium alloy is used only in the manufacture of professional cassettes, since they are obtained at a price like “gold”. The weight of titanium cassettes is noticeably lower than that of steel cassettes, and are similar in strength.
Differences by bike type
Mountain bike cassettes contain a sprocket with a sprocket range from 11-28 to 11-36, i.e. 8.9 and 10 stars. For road bikes, cassettes are used with a range of stars from 11. 22 to 11. 27, namely from 8 to 11 stars. It is worth noting that mountain cassettes are compatible with road cassettes if the number of stars is the same.
How to replace the shift cable on a bicycle?
There is no special science in shifting gears on a bicycle; at first glance, everything is simple. Two levers on the left, two on the right, or even just a grip-shift. what could be easier. But nevertheless, observing novice cyclists, one may notice not entirely correct and coordinated actions. But consistency when cycling is the most important thing! This is the only way you will be able to move as efficiently as possible on a bicycle, make maneuvers, overcome obstacles.
As an example, we will consider the most ordinary mountain bike (MTB) with three stars in front and 8-9 in the back.
Let’s immediately highlight the most common errors and problems:
- Too heavy gear is a common mistake. Many newbies even say that 44 (or even 48) stars in front are not enough for them. It’s a delusion. Constantly spinning a heavy gear you are simply killing your knees. Try to keep track of your cadence (cadence) until it becomes automatic. You can even count the number of revolutions per minute for fun. If about 90-100, then this is very good. And so, gear 44-11 is enough to accelerate on the plain to
60 km / h. So try to convince those who say that 44 stars are not enough for the city. By doing this, you may help to keep people healthy.
1500 km). As a result, when the load on the pedals increases, the chain slips and the pedals fail unpleasantly. This must be taken into account and travel more carefully until everything gets used to it. Even for a fairly strong cassette, the rubbing period is about 200 kilometers.
If you are new to the saddle, pay a lot of attention to pedaling, shifting, try to work with both the front and rear derailleurs. Try to choose a gear depending on the maneuver being made. For example: you slow down, but you will need to accelerate for this. Shift the gear lighter even when braking, then it will accelerate faster.
The clarity of gear shifting is highly dependent on the technical condition of the bike components. Monitor and, if necessary, replace the cables and shirts in time, the rear derailleur rollers, the switches themselves, the drive elements. the chain, cassette, front sprockets.
Front derailleur setting
The front derailleur is even easier to adjust than the rear derailleur. But it is important that it is properly secured to the bike frame. When the chain is on the largest sprocket, the sprocket to derailleur frame should be 1 to 3 mm. And the frame should be parallel to the stars. If so, then you can start customizing.
Set the speed to minimum. the rear is the largest and the front is the smallest star. Loosen the cable tension and turn the screw marked L (Low (where it is visible in the picture) until there is a millimeter gap between the chain and the derailleur frame. he lay in a special groove near the screw.
Now we set the maximum speed when the front chain is on the largest sprocket, and on the smaller cassette, and we turn the screw marked H (High) so that the gap between the chain and the inner plane of the frame is a millimeter. If, after that, the chain still reluctantly climbs onto a large sprocket, slightly unscrew the screw H.
Now we sit on the bike and try how successful the gearshift settings were. If the chain does not shift well to low speed (smaller chainrings), twist the cable tension adjuster located on the front derailleur coin on the handlebar to loosen the cable tension. When the chain sluggishly climbs onto large sprockets, tighten the cable with the same adjuster.
If the chain slips with effort when pedaling, it means that it is stretched and it is time to change it. If you haven’t changed it for a long time, you may also have to change the stars with the cassette. a worn out chain quickly destroys a star.
If some certain speeds do not turn on well, check if the cable runs freely in the shirts and if there are any breaks, as well as places with unbraided cable winding. Shirts with breaks and those in which the cable runs with difficulty must be replaced, as can a damaged cable. The same problem can be caused by a bent cock.
If the switch suddenly stopped working altogether, then the problem is definitely in the cable: either it is badly tightened with the fixing bolt, or it broke.
And another important point. When changing gears, make sure that there is no skewing of the chain, due to its location simultaneously on opposite sprockets of the connecting rod and cassette, as well as on the middle sprocket and extreme sprockets of the cassette. Incorrect circuit arrangement is shown schematically in the picture. Because of this, there is a rapid wear of both the chain and the stars.
In general, setting up your bike’s gear shifters is quick (30-40 minutes) and effortless.
How to fix a figure eight on a bicycle wheel
Wheel bending is an unpleasant thing
If your wheel is bent and you don’t know how to fix it, you are in the right place. I have already come across this problem and will tell you simply. repair is possible. everything is quite simple. over, I will say that the problem that you are faced with will most likely arise at an enviable frequency if you love your bike and ride it several times a week. Therefore, it is worth learning this once, so that in the future you can remove the breakdown yourself every time it occurs.
- How defects can form and why?
- What tools we may need to eliminate defects?
- General algorithm for eliminating problems with a deformed wheel
- How to straighten a wheel in practice and how to determine exactly where the figure eight goes on a bicycle wheel
- Video. How to fix a figure eight on a bicycle wheel video
Also, be sure to read the pressure to inflate the wheels of the bike here.
How to tell if your wheel is OK. Simply place the bike upside down on the saddle and on the handlebars, wheels up. Spin the problematic wheel, as you think, (spin it in the sense of rotating it around its axis) and check it “by eye” first. If everything is in order with the wheel, then it will rotate around the axis absolutely evenly. If there is a figure eight, then it should be visible to the naked eye or, more often than not, something like the beating of a wheel in a certain place. It is necessary to look at the wheel in profile and face, since the bending of the wheel can occur in different directions.
Types of bends that are possible in principle:
- the most common type of defects is a wheel eight;
The eight wheel tilted to the left, the dotted line shows how it should be.
The wheel is curved like an egg. The dotted line shows how it should be.
Umbrella curvature. Dotted line as it should be.
How defects can form and why
There is a widespread belief that a wheel can change its shape if you do not ride carefully, when driving over bumps or during unsuccessful jumps. This is all true. That is, all this, of course, affects the rapid wear. But that’s not the only reason a wheel can break. When the cyclist gets on the bike, the wheels are already being loaded in the vertical direction. Further, when braking at speeds, the wheels can deform, forming eights. When maneuvering (cornering) in any direction and hard braking. In general, I think you can not explain what sloppy driving is, you yourself understand everything perfectly. So caring for your bike can put off the problem, but over time you will come back to it anyway. Even if you ride very carefully on a good road, such is the specificity of a bicycle.
Everything, of course, still depends to a large extent on the wheel rim itself, on its physical characteristics. Therefore, when buying a bicycle, you need to pay the seller’s attention to such things, wondering how long the wheels can last, how they react to the deformations described above. So on cheap bicycles, the rims are correspondingly less strong. And various bends (egg and eights) of wheels can form much earlier than on their more expensive and high-quality counterparts.
In general, how the problem can arise, I think you already understood. So let’s get straight to how to solve the problem and align your wheel.
What tools we may need to eliminate defects
So, to fix your wheel you may need:
- spoke key
- crayon or something that can draw on the rim of the wheel (water marker)
- universal plastic assemblies for dismantling bicycle tires.
We need the spoke wrench to loosen and tighten the wheel spokes. I must say right away that you won’t have to pull up much. You will gradually tighten the knitting needles and check the results immediately.
General algorithm for eliminating problems with a deformed wheel
The general algorithm is as follows. we determine in which specific place the figure eight begins and where it ends (we select the lesion focus). The next step is to find the center needle in the figure eight and work with it. If our figure eight falls to the left side, select the spoke on the opposite side and pull it up a distance of less than one turn of the spoke key. Then we take two adjacent knitting needles. these will be knitting needles already on the opposite side of the previous knitting needle. weaken them by the number of revolutions a little less (for example, 2 times less) than we tightened the previous knitting needle. And so on until fully straightened. That is, the next two knitting needles (they will be placed on the opposite side) are already tightening even weaker than the very first knitting needle. As you move away from the central spoke (lesion focus), the number of revolutions, respectively, will also decrease gradually.
If the figure eight is small by three needles.
So, again, how do you fix an eight on a bike? To fix the wheel, we select a section where there is an eight, and along the length of this entire section we loosen and tighten the spokes going one after the other. We loosen the spokes on one side of the wheel, and tighten them on the other. When the required operations have been completed with all the spokes, we rotate the wheel again and see the correct movement of the wheel around the axis. If it becomes worse, return the knitting needles to their previous place and make the tightening-weakening less. Thus, the skew in one direction leading to the figure eight will gradually level out. To perfectly align the figure eight, you will have to patiently and painstakingly perform all of the above actions slowly (i.e. we twist a little).
Eight larger. to be treated as well as small.
The wheel is flattened by an egg, the straightening algorithm is slightly different. We only pull up the right side.
How to straighten a wheel in practice and how to determine exactly where the eight of a bicycle wheel goes
How to determine exactly where the eight passes. Masters who have gotten their hands on in this matter can fix the problem without improvised means (crayons and other things). You will have to edit the wheel first using chalk. We spin (rotate) the wheel and gradually bring the chalk to the rim of the wheel rotating in the axle. In those places where there is an eight, the chalk will touch the rim and scribble serifs on it. So you define an eight for yourself.
I saw another great option on how to straighten the figure eight on a bicycle wheel in one video. We take ear sticks. On both sides of the wheel we have front fork stays. We attach ear sticks to these feathers on scotch tape from both sides and, just like with a crayon, rotating the wheel, gradually bring the ear sticks to the wheel rim and the places where they begin to clearly touch the rim. mark with chalk. Quite a convenient option, since it can be quite problematic to hold the chalk on the weight. If your wheel is flattened like an egg, that is, it has lost its perfectly round shape, we do everything the same as for the figure eight, only we bring the chalk from the outside of the rim. where the tire with the camera should be.
As you can see from the above, the elimination of the figure eight on a bicycle is not a very difficult process, and what is most pleasant is that it is accessible to everyone. The only thing I want to add is that when you’ve done all the work of aligning the figure eight on the bike, be sure to check all the other spokes. What shouldn’t be? The needles should not be loose or overtightened. Loose spokes can break, so carefully tighten them and repeat the wheel adjustment again. If the spokes are too tight, they can pierce the pin or wheel rim. Craftsmen advise if you have tuned the wheel and everything suits you, but some spokes stick out from the wheel rim, you can sharpen them with a file so as not to pierce the camera.
As a result, I would like to say that it is better to learn to do all this yourself once. than to go to the workshop every time. Personally, I remember the workshops as would-be masters who do not have time to serve everyone, so they do everything in haste. And you are the owner of the bike and you can do everything unhurriedly, unhurriedly, literally and accurately. So go ahead and buy spoke wrenches and fix your bike wheels!
Pedals on the bike find out the reason here.
See more about fixing the figure eight on a bicycle in the video below so that everything finally fits in your head with a clear picture.
Can Cycling Cause Scythian Disease
Everyone considers the bike to be the perfect trainer for developing body and spirit. This is really a great option for those who want to join the sport regardless of their age and their own build. After all, everyone can ride a bicycle. And if such a ride definitely improves the psychological state. stress goes away, a feeling of freedom arises, then physical health can sometimes undermine, and seriously.
Exacerbation of chronic diseases
Scythian disease is rare, but is still called prostatitis. In ancient times, nomads, in particular the Scythians, often suffered from this ailment due to constant shaking from horseback riding and long sitting in the saddle. At this moment, congestion occurs in the prostate, in the testicles, which often contributes to the development of inflammatory processes in them. Is it possible that a long bike ride can also trigger the onset of prostatitis? Urologists of the Department of General Medical Practice of the Belarusian State Medical University believe that no. Even long cycling trips cannot do any harm to a healthy person. But the presence of chronic diseases with a high probability will immediately make itself felt. In such cases, not only the already diseased prostate is often inflamed, but also the existing hemorrhoids. And more recently, a seemingly “extinct” disease from one hour of cycling can turn into an acute pain attack. Therefore, it is better for people suffering from any chronic diseases in the groin area to completely abandon the bike. And for everyone else, such activities will only give health and energy.
Development against the background of a bacterial infection
Urological surgeons from the Clinic of Urology. R. M. Fronshtein of the First Moscow State Medical University. IM Sechenov called the real development of acute prostatitis against the background of a bacterial infection. It so happens that a cyclist on his feet, or, in this case, on bicycle wheels, suffers a minor cold illness. Against the background of a runny nose and cough, pain in the groin also occurs, which the man ignores for a month or two, and at this time does not sit on the bike. And then all the discomfort goes away and it seems to the person that his general health has been restored. But in fact, the disease has passed into a chronic stage and now prostatitis can be almost asymptomatic for years. The only thing is more frequent urination. However, as early as the next summer season, even a relatively short bike ride is likely to immediately exacerbate the now chronic prostatitis and the pain will be so strong that you cannot do without medical help.
Research says no
Spanish scientists for several years in a row warned their compatriots that from the side of a bicycle saddle on the perineum and reproductive organs of men such pressure is exerted that they, at least, become infertile, and in the worst cases, serious diseases develop in the prostate and testicles. Doctors from the Puigvert Clinical Institute of Urology in Barcelona decided to end this debate and examined the health of more than 5,000 cyclists. This involved a cross-sectional analysis of data provided by professional cyclists as well as those men who used their bike daily to commute to work. Volunteers were asked about their age, education, duration of cycling, average mileage per week, height, weight, heart rate, as well as attitudes towards alcohol, smoking, history of cardiovascular and cancer diseases, and diabetes. Separately, all surveyed men were asked to indicate whether they had suffered from erectile dysfunction, infertility, prostatitis or prostate cancer in the past five years. An analysis conducted by Spanish doctors did not reveal any connection between men’s health problems and people’s hobby for cycling. Even in those men who spent more than eight hours a week in the saddle, the researchers found no andrological abnormalities.
Real fact proves otherwise
Lance Armstrong, one of America’s most famous road cyclists, who finished first in the Tour de France seven times, told reporters in the late 1990s that he had been diagnosed with advanced testicular cancer. At the time of the detection of oncology, metastases had already spread into the abdominal cavity, into the lungs and even into the athlete’s brain, that is, this terrible disease had been almost asymptomatic for him for many years. Doctors made the assumption that cancer, which completely affected one of his testicles and partially the second, most likely provoked the athlete’s professional activities. Lance Armstrong only managed to overcome the disease thanks to his courage and the latest aggressive methods of chemotherapy, but this became an ominous warning to all professional cyclists. men and other lovers of long bike rides.