Chain replacement. how and when to change
The chain has the highest wear rate in the entire transmission group for any bicycle. Chain wear is reflected in chain lengthening. Therefore, it should be changed from time to time in order to maintain the accuracy of the transmission shift. In addition, the worn chain begins to “eat up” the sprockets on the cassette and connecting rods, sometimes they can even break. However, even wear of all rubbing components of the transmission is not so bad. Much more dangerous is the more pronounced stretching of individual chain links and the abrasion of groups of teeth on the stars. This is due to improper mounting of components or a disturbance in the plane-parallelism between the stars.
Example of chain abrasion on derailleur rollers
So when exactly should you change the chain? Chain wear depends on a number of factors: maintenance (cleaning / lubrication), operating conditions (water / mud / sand), the rider’s riding style and the overall condition of the transmission (cassette and sprocket wear). That is why it is not entirely correct to determine the wear of the chain by the number of kilometers rolled on it.
Campagnolo, a world leader in transmissions, Joshua Riddle says: “It’s hard to boil it down to kilometers because riders have different weights, ride differently, switch more or less often, deliver different power, ride on flat or mountainous terrain. on dry land or in terrible weather conditions, taking care of the transmission or driving on muddy… all this adds up to a completely different picture of chain wear. The chain can run from 3000 to 8000 km when rounded, but it can be even less or even more, in some cases. “
The chain must be replaced with a rhinestone if you find any damage or cracks on it. After all, its unexpected rupture occurs, as a rule, at the time of application of the peak load, because of which the leg falls sharply into the void, all this leads to a fall. It is also helpful to regularly check the chain for wear.
Next, we will describe several simple ways to assess the state of the chain.
Measuring with a ruler
You can measure wear with a simple ruler, it is especially convenient to use an inch scale, since two links must correspond to 1 inch. Take one reference pin and measure out 24 links (12 full if you count the narrow wide as the full link). On a new chain, 12 full links should equal 12 inches. But on a worn and lengthened chain, 12 links will be longer. If the pin of the chain of the 12th full link is displaced by more than 1/16 inch, then it is time to change the chain.
If the inch ruler is not at hand, then you can use a metric ruler, then it is more convenient to measure at 10 links. On a new chain, 10 full links will equal 25.4cm. If the distance between the centers of the links of the chain is more than 25.5 cm, then the chain is considered worn out and requires replacement. Everything
Measurement with a gauge
Chain gauge is a very simple, inexpensive and useful tool for measuring wear.
It is necessary to hook one link with a hook, and if the head on the other side freely goes inside the chain, then the wear has gone beyond the percentage indicated on both sides. One side is designed to indicate 0.5% wear, the other 0.75%. It is recommended to change after 0.75% starts to go.
All the above measurements are best taken with the chain removed from the bike to eliminate the contribution of chain wear to the measurement.
Bicycle chain wear
After the brake pads, the chain is the most worn out part of the bike, as it is part of the drive. With long-term use, the chain stretches due to the appearance of backlash between the holes in the plates and the pins where they are pressed. Bicycle chain wear occurs for several reasons:
Chain misalignment with different gear options. 2. Loads arising in the links when the chain moves from one star to another when switching. 3. Since the chain works in the open state, dust, dirt and other objects falling into the links, due to friction, increase the wear of the chain.
On bicycles, single-row roller chains with a link length of 1/2 inch. 12.7 mm are used. Ideally, a new chain should have a length of 12.7 times the number of links in the chain. How to find out the state of chain wear in order to control the situation and change the chain in time, prolonging the life of the cassette?
How to determine wear on a bicycle chain
Take a section of the chain with the number of links in it. 20. Multiplying the number of links by the length of the standard link 12.7 mm, we get the size of the section of the new chain of 20 links, equal to 254 mm. We take a ruler and measure.
The photographs show that the distance between the extreme centers of the 20 links is approximately 254 mm.
In this photo, the distance of the 20 links is just over 255mm. The difference between the first and second case is 1.1 mm or 0.45%.
When to change the chain. n indicators as a percentage
When measuring chain stretch using 20 links as an example. (the length of the new chain at 20 links is 254 mm).
Excessive wear of the chain, in addition to indistinct gear engagement, also contributes to accelerated wear of the cassette stars. To control this process, there are three approaches to using a chain on a bicycle.
Riding to the extreme limit of chain stretch (0.5%). Regular measurement and control of the chain size, especially after 1000 km of run and its timely replacement.
Circular replacement. Having three chains, you can change them sequentially one after another in a circle, after 500. 1000 km, without waiting for complete wear. This method is usually used when using a chain and cassette of the same price range.
Replacement frequency. Every 1000. 2000 km, simply install a new chain. The method still does not exclude regular control, but it significantly allows you to save the bicycle cassette.
To prolong the life of your bike’s drivetrain components, you need to regularly clean and lubricate the chain.
Also read on this topic:
Bicycle chain. The invention of the chain drive over a hundred years ago was one of the revolutionary steps in the development of the bicycle. With the help of the chain, it became possible to transfer the force from the pedals to the rear wheel of the bicycle, which made it possible to reduce the size of the wheels to.
Bicycle chain maintenance. The new chain is treated with grease. This is done to preserve the chain during storage. This lubricant will last until the first cleaning of the chain. There is no need to wash it out, as it works well and performs its functions much longer than liquid lubricants.
Scheme for preventive bicycle lubrication. Consider a preventive bike lubrication scheme. these are the points on the bike that are lubricated regularly after multiple rides. And also after hitting the bike in the rain or before a long ride.
How to avoid puncture. After each ride, pay attention to the condition of the bicycle wheels. A cursory inspection of the tires will allow you to find stuck objects that have not yet entered the inside, and although the pressure in the wheel is normal, then on the next trip this problem will come out.
Replacement of tires and tubes. Tire and tube replacement does not require a large set of tools. If you have disc brakes, then after opening the eccentric and unscrewing the nut, the wheel comes out of the fork without problems. often there are V-BRAKE rim brakes, where the pads are located.
When and how to replace the timing chain. step by step instructions
Often, car owners have to replace the timing chain. This detail should be given close attention, since the well-coordinated operation of the gas distribution mechanism depends on it. In this case, the correctness and sequence of the procedure plays a decisive role in the correct operation of the engine.
Why change the timing chain
During the operation of the engine, huge loads are imposed on this part, which, after a certain mileage, can completely lead to a circuit break. In this case, the damage can be partial, for example, when one of the links breaks off from it. In this case, the mechanism continues to work, but slippage is observed, the engine starts to work intermittently. Since the part is located inside the motor, then, even with the slightest errors, the consequences can be the most unpredictable. From this it follows that the timing chain must be changed in a timely manner. If you are a fan of long trips, then it will not be superfluous to carry a spare part, especially since it will not take up much space.
How to determine wear
As already noted, the chain is subjected to serious stress during operation. As a result, the part stretches over time, the links of the links wear out. Sooner or later, such a part may jump by one or more teeth. Depending on the engine, this can be dire. To avoid unpleasant consequences, you need to replace the chain in accordance with the recommendations of the manufacturer of your car. The opinions of experts that it is possible to determine the wear of a part by sound differ. Some believe that this is impossible, others are of the opinion that the condition can be determined by the following signs:
- In the area of the timing drive, a characteristic ringing noise appears. It can also be accompanied by small bumps. Gradually, the ringing can increase, which will lead to the occurrence of shocks.
- When the chain is stretched, the valve timing is shifted. As a result, fuel injection will be either early or late. This ignites the unburned fuel in the muffler. If there are shots in the exhaust system, one can judge a malfunction of the timing system and, in particular, the chain.
The part in question has a certain resource. Depending on the engine and operating conditions, it can be within 30-160 thousand km. Even taking into account the recommendations of the manufacturer and observing the replacement deadlines, the figures in reality may differ. The car can be operated in a wide variety of conditions and sometimes quite difficult. The manufacturer conducts tests of its cars at the test site, and daily operation in city traffic jams affects much more engine wear. Weather conditions also affect the timing of replacement parts. Despite the fact that the timing belt and chain perform the same function and the chain lasts much longer, you should not forget about its timely replacement.
What can damage to the timing chain cause
Today there are many power units, both modern and old brands, in which the arrangement of valves and pistons is made in one block. During the operation of the pistons in the cylinder, fuel and air move. In simple terms, at the moment when the piston is in the upper position, the valves are closed. At this moment, the fuel-air mixture ignites. When the piston is in the down position, the valves open for exhaust and fuel intake. Thus, the correct operation of the entire mechanism occurs, and most importantly, synchronous.
If a break occurs, then this synchronicity is broken. As a result, the piston strikes the valve, the valve bends, and the piston may be damaged. The engine will not be able to work in the previous mode; it will require serious and sometimes expensive repairs. There are times when you can get by with low costs. But not only the breakage of the chain is important, but also its stretching, which has already been noted above.
When is it time to change
Some manufacturers assure that the part does not need to be replaced during the entire life of the car. This statement is appropriate for the ideal operating conditions of the car. Nevertheless, it is better to replace a part every 100 thousand km. mileage. If a metallic ringing or knocking is heard during engine operation, then, most likely, the chain is stretched and it overshoots. With such symptoms, replacement should be urgent. The need for replacement can be judged by the thick bluish exhaust, a drop in engine power, loud noises in the muffler, a sharp increase in engine temperature for no apparent reason. In most cases, these signs appear together and indicate wear on this part.
If you purchased a used car, then you definitely need to pay attention to the timing chain. Even if the former owner said he recently replaced it. There are some cars that have a special indicator on the instrument panel that signals in case of problems with the gas distribution mechanism. If the chain is untimely replaced, it will slip, causing damage to the block head. At best, this will lead to bent valves, at worst, the cylinder block will have to be replaced, since it will simply become unusable.
How to choose the right new part
So, we figured out when the engine needs replacement of the part in question. But, how to choose it correctly, because the chain can be either single-row or double-row. Each option has its own pros and cons:
- The single-strand chain provides a slight increase in motor power and helps to reduce noise. This is due to the fact that it is easier for the engine to scroll one row than two.
- Despite the fact that the double-row chain is more noisy, it is endowed with more reliability. It is characterized by a longer service life.
In addition, the chains have a different number of links. Different types of chains can be used depending on the brand of machine and the type of motor. If we consider such cars as the VAZ 2101 and 2102 with a 1.2 and 1.3 liter power unit installed on them, then they are equipped with a part for 114 links. For vehicles with 1.5, 1.6 and 1.7 liter power units, a chain with 116 links is used, respectively. This applies to the models VAZ 2103, 2107 and 21213. When replacing the chain, it is necessary to clarify the information in the corresponding document for the car.
Do-it-yourself timing chain replacement
The procedure requires attention and accuracy. If you are used to doing auto repairs yourself, then replacing the chain should not cause any particular difficulties. Before starting work, you must prepare the appropriate tools. The list may differ depending on the car brand. We will consider replacing a part using the example of the Nissan Almera. You will need the following set of tools:
- hex key 6;
- heads 12, 13, 14;
- chisel and small hammer;
- containers so that liquids can be drained;
- torque and adjustable wrenches;
- block of wood;
- degreaser and sealant;
- new chain.
The dismantling procedure is carried out as follows:
- We start by removing the wires from the ignition coils and twisting them. We remove the details to the side. In order not to confuse anything during the assembly process, it is better to number everything.
- Air hoses are removed from the valve cover. The cover is secured with bolts. It will also need to be removed, then access to the chain will open.
- The right engine mount is removed. Otherwise, it will interfere with disassembly.
- We substitute a suitable container, unscrew the plug and drain the engine oil. We wait until it is completely drained, remove the oil filter.
- We take another container and drain the antifreeze from the radiator, while opening the lid so that the glass liquid is completely.
- Further, the cooling radiator is dismantled, the generator drive belt and the clamp of the inlet pipe are removed.
- The next stage is dismantling the cylinder head. The head cover of the assembly is fixed with four screws. We unscrew them and remove the cover along with the fan and related elements.
- You will need to unscrew the motor pan. To do this, remove the muffler, the fastening of which is made with several bolts.
- We loosen the screws securing the pump pulley. This will remove the belts that are suitable for the climate and control system.
- Find a place between the crankshaft and the side of the crankcase. Here you need to place a wooden block and remove the crankshaft pulley. To unscrew the bolt, use a head of the required size.
- Next, remove the pump pulley. Under it is a gasket, which also needs to be removed. The oil pump is also dismantled for a while.
- This completes the preparation for removing the chain. You can start dismantling it. The camshaft gears are secured with screws that need to be removed. The camshaft is fixed with an adjustable wrench.
The chain is dismantled in the following sequence:
- The chain damper is removed (bar at the top).
- We remove the tensioner and the bar, which is responsible for the tension of the damper. The tensioner must be carefully inspected, and may need to be replaced.
- The bottom placket is put on a hairpin.
- Remove the chain.
- Using a flat screwdriver, remove the gear located below.
- Now you can compare the new part with the old one. The difference should be noticeable: the old chain will have a longer length.
- Next, they install a new chain, lubricating it with engine oil.
- The assembly process is carried out in reverse order. All parts of the mechanism must be cleaned. Use a degreaser and a clean rag to clean the side of the engine.
- To install the chain correctly, you need to ensure that the mark on it coincides with the marks on the pulleys. Next, the side of the motor is lubricated with sealant, the bolts are tightened to secure the cover. Wait a while for the sealant to dry. All subsequent assembly steps are performed in reverse order.
example of replacement on a Nissan Almera car. How can it be located
Usually, in motors with a timing chain drive, its location can be front or rear. The first option involves the installation of the drive from the side of the drive element. In the second version, the drive is located on the side of the gearbox and flywheel. Front location is the most common and there is a logical explanation for this: easier repair and maintenance. Despite less popularity, the second option is also used, with such well-known brands as Audi and BMW.
According to the manufacturers, the drive element ruptures as a result of not following the recommendations given in the instruction manual. The chain is closely related to a part such as a tensioner. It may fail due to the use of low-quality oil. Its service life also depends on the pressure in the lubrication system. If the engine consumes oil and no action is taken to correct the problem, the pressure in the system will decrease over time. As a result, the chain will not be properly tensioned, which will lead to its breaking.
Chain tension after replacement
After the replacement of the part is completed, its tension will be required. Consider as an example a VAZ 2101 car. Before proceeding with the procedure, you need to make sure that there is no mechanical damage to the main timing elements, for which the valve cover is removed. If there are defects, the damaged parts are replaced. To tension the chain you will need:
- keys for 13 and 38;
- flat screwdriver;
The car is pre-installed on a convenient platform, stops are placed under the wheels to avoid accidental movement. The gearshift lever (gearbox) is switched to neutral. Further:
- The tensioner is located near the water pump under the pipes. Use the 13 key to release it. When loosening the chain, the shoe should snap off.
- With a 38 key, turn the crankshaft pulley 2 turns clockwise.
- The shaft is turned until the marks on the bearing housing and on the camshaft match. When cranking the crankshaft, the required chain tension will occur.
- Use a screwdriver to check the tension. If the chain is taut, then tighten the tensioner with a 13 key.
how to properly adjust chain tensioners
After the steps taken, you need to check the operation of the engine. There should be no extraneous noise. If they remain, then the reason may be a sedative. In this case, check its serviceability and, if necessary, replace it.
Important: when adjusting the chain tension, you need to follow the marks so that the valve timing does not change.
It is important to replace the timing chain in a timely and correct manner. You can do the procedure yourself, following the step-by-step instructions.
What to do if the chain slips under load on the bike?
A bicycle is a complex of parts and movable mechanisms, which tend to wear out and break over time. One of the popular problems is when the chain slips, what to do? It is quite simple to get an answer to this question if you know the design features of a two-wheeled vehicle. It is also important to take into account the type of bike, operating conditions, maintenance of the technical condition of the device. Thus, you can significantly reduce the wear of all parts, ensure the performance of the bike and a comfortable ride.
Causes of chain problems
Even the simplest bicycle has a complex of interconnected parts. The precise and uninterrupted functioning of each element ensures the reliability and performance of the equipment. For example, many cycling enthusiasts have a question: the chain slips, what to do? To get an answer, you need to determine and eliminate the causes of such a situation, and for this it is worth knowing the design features of the vehicle.
One of the main parts of the bike is the chain, which is stretched over the stars. Due to the rotation of these elements, movement along the track is carried out. In this case, even the simplest systems can fail, that is, the chain will begin to slip. This situation can arise for the following reasons:
- Significant wear of the chain links, which leads to the elongation of this element;
- Due to wear, the teeth of the front and rear sprockets are grinded;
- Too much wear on the cassette stars;
- The simultaneous impact of the above factors.
Long-term and intensive operation of a bicycle without maintaining the technical condition, timely replacement of parts and their lubrication inevitably leads to disruptions in the performance of equipment. Most often, the chain slips due to a lack of proper and quality bike maintenance. That is why it is important to properly care for the technical device, performing inspection, lubrication and replacement of parts in a timely and regular manner.
One of the common reasons for the rapid wear of the transmission is incorrect gear shifting. In any case, the sprockets, chain and all parts of the moving mechanism need regular maintenance in order to keep the bike in good working order. Timely lubrication of elements, replacement and careful operation of equipment allows you to avoid a long-term occurrence of such a situation when the chain jumps on a bicycle under load.
After finding the answer to the question about the cause of the chain malfunction when the bike is loaded, it is worth subjecting the technician to repair. Such an event can be carried out independently, because the main reasons for parts wear and breakdown are known. In this case, all actions should be carried out very carefully, and the old elements must be replaced with new ones with suitable dimensions. Such a careful approach allows you to quickly and efficiently change the necessary parts of the system and ensure the bike’s performance under optimal load.
With large stretching of the links, the probability of damage to small and medium stars is quite high. Therefore, a thorough examination of these elements is important and allows you to determine the next steps. If the sprockets are worn, the sprockets of the required size should be selected and the cassette renewed. An alternative option for replacing parts is to install a special “damper”, which maximizes the life of damaged elements. Such a device is often used in cycling and prevents the chain from flying off the stars.
One of the most common causes of circuit problems is inaccurate switch settings. In this case, the bike chain slips under load. In this case, it is necessary to adjust the switches, and for this you need to set a suitable tension for all cables, adjust the travel in the lowest gears and optimize the travel in large stars. In this case, you should take into account the features and characteristics of technology.