How to replace front sprockets on a bike?
Change chainrings on your bike with our step-by-step video tutorial. Replacing the sprockets on a road or mountain bike is a fairly straightforward task, but one that needs to be done urgently when the cogs wear out. You can swap chainrings to change the gear ratio, lowering which will make it easier to climb slopes, and increasing it will speed up in flat races.
Before starting work, find out the exact landing diameter (PDD) of your leading star system before purchasing new ones. Typically PDZ 110 or 130 mm. or significantly reduced or traditional size. If the bike is equipped with a 50x34T system, then the PDR is almost certainly 110 mm. If it is 53x39T, then the PDZ will be 130 mm.
Of course, you can always measure the circumference of your system to be sure. There are exceptions, such as the “four feet” used in Shimano’s newest 11 speed hitch, for which sprockets of various sizes are available without worrying about the difference in PDL.
How to replace asterisks?
If your goal is not just to replace the outer sprocket. which can be easily done by removing the fasteners and threading it through the connecting rod. you will have to start by removing the drive sprockets. 2. Some high-quality connecting rod systems allow you to remove the sprocket bolts with regular hexagons or special Torx wrenches, but if your sprockets have regular bolts, you need either a special puller wrench placed in the slotted groove of the sprocket nut or another hexagon (often 1 mm larger than the front) to keep the nut from turning. Special key. a puller holds the sprocket nut immobile while unscrewing or tightening the bolt.
Lock the nut and unscrew the bolts counterclockwise. Remove them carefully, they will come in handy for installing new sprockets. You can now remove the old chainrings or clean them thoroughly if you replace only the outer chainring to change the gear ratio.
When replacing the asterisks, you need to pay attention to their relative position.
The outer star, usually the largest, has a small pin protruding from one side. The sprocket should be positioned so that the pin is behind the connecting rod in order to avoid complete seizure of the chain in the event of its dismounting and falling between the outer sprocket and the connecting rod. The inner sprocket usually has a small mark in the middle of the outer edge, which should also be placed behind the crank.
The chamfered edges of the cogs. which aid in gear shifting. either the brand name or any other markings must be visible from the outside when the sprocket is installed.
Install the sprocket with the marking outward, thereby correctly positioning the teeth for smooth gear shifting. When the sprockets are positioned correctly, insert the nuts into the holes. Fix them with a special wrench or hexagons, then screw the bolt into the nut clockwise until you feel a slight resistance, while fastening the sprockets.
Easiest way to remove the front sprocket nut off a motorcycle
Repeat these steps for all bolts, then alternately tighten each bolt a quarter turn at a time until it stops. A torque wrench can be used to do this by tightening the bolts to the torque indicated on the bolts.
Install the sprocket connecting rod onto the axle, remembering to thread them through the chain. Pedal and change gears to make sure everything is working properly. If you have resized the outer sprocket, you may need to readjust the front derailleur for smoother speed changes.
Dismantling the transmission cassette
The rear of the transmission is not too difficult to disassemble, all that is needed is time and a few tools: a cassette puller, a whip and wrenches (open-end. for removing a wheel and an adjustable. for a cassette).
The first thing to do is to free the bike from the rear wheel. Using a wrench, the nuts are unscrewed, and the chain is dropped from the rear sprockets. On a mountain bike, it is usually a matter of a second to remove and put on the wheel, thanks to the eccentric fastening.
The removable device is installed on the slotted nut of the cassette. A whip. a small flat “knife” with a fragment of a chain. is needed to keep the cassette from turning. With the help of an adjustable wrench, we rotate the puller, we direct the whip in the opposite direction, or, more simply, we hold it with a large star of the system.
To unscrew the nut, you will need to sweat a little, and not only in the first stage. With the same good effort, the stars will need to be returned to their place. Once the nut has folded, the cassette can be safely unhooked from the wheel. Now it remains to examine it and determine which star needs to be pulled out.
Some of the outer small sprockets can be removed immediately when removing the cassette. They should be cleaned and inspected for wear. The same is done with the main sprockets: it is determined how much they are worn out and which ones are the most.
How to remove rear sprockets from a bike
The bike drivetrain requires periodic maintenance. The most common problems are chain wear and failure of one or more sprockets on the cassette. Wear is also true for a single-speed one, the only difference is that the chain and the star itself are designed for longer operation.
The worn out part of the transmission negatively affects its entire operation, therefore the used sprocket will need to be replaced. Especially this problem pops up on asterisks that are used too often, which, in principle, is logical. Before changing, it is necessary to remove the worn-out sprocket from the rear wheel, which we will talk about further.
Removing and installing a star on cassettes
Unlike ratchets, in this system the stars can be changed individually. All that is needed is to remove the old part and put a new one in its place. Special rivets and small spacers are located between the stars, which allow them to hold a fixed position and facilitate the installation of the cassette itself. It is very easy to screw the desired star from the device, the main thing is not to get confused in the sequence, especially on large cassettes of high-speed mountain bikes.
Sometimes “spiders” can be found on cassettes. rigidly fixed areas of several stars. Here you will have to replace the entire set, on which one of the stars is badly worn out. True, this only applies to large transmission rear wheel sprockets.
When replacing a single chainring, you may encounter the problem of the difficulty of switching the chain to it. This is due to the fact that the chain already has wear compared to the new sprocket. And if this is not so noticeable with one detail, then several new stars will immediately bring a tangible dissonance to the operation of the transmission. That is why it is advisable to change the cassette at the same time as the chain.
A little about singlespeed
To remove the rear transmission sprocket from a single speed bike, you only need to open the retaining ring. Among singspeed lovers, you can hear that the regular ring is useless and can break itself, even if you did not think about changing the star. Perhaps this is so. In any case, if the stopper is damaged, we change it to a new one, otherwise backlash cannot be avoided (the chain simply dangles from side to side).
It is also very simple to assemble such a structure: the ring is literally put on its own, you don’t even need to squeeze it. It’s that simple on single-speed bikes! You shouldn’t just wedge yourself into the transmission of a bicycle with one gear. Common reasons are a badly worn part or the need to install a new sprocket with a larger diameter.
As you know, without serviceable stars and a chain, a great will not even be able to get under way. Timely replacement of transmission system components is the most important component of any type of bike repair. from simple two-wheeled road bugs to road and mountain superbikes.
How to remove and put a system star
The system is a set of three chainrings. If you often have to ride at speed, then most likely the largest sprocket will wear out. Conversely, with frequent off-road trips, wear will affect the first (smallest) sprocket. By analogy with the second, middle sprocket, when the bike is used at medium speeds in conditions of a dirt road or bad asphalt.
On a modern mountain or road bike, the system is collapsible, so it will not be difficult to dismantle all the stars. Before work, you need to carefully prepare, namely, collect all the necessary tools:
- connecting rod puller;
- spanner key;
- new detail;
- clean cloth and grease.
Removing the system from the bike: 1. Place the frame in an upright position. If you have a stand, you should definitely use it.
Remove the right crankshaft axle fixing bolt with a hexagon.
Unscrew the pedal from the right crank arm. A standard open-end wrench is suitable for this.
Insert the puller into the connecting rod to remove it from the carriage. To begin with, we screw the tool all the way into the thread. It is important that it sits flat on the shaft, otherwise the axle can be damaged when unscrewing the connecting rod. Place the spanner wrench on the puller and screw it in until it stops until the connecting rod is pushed out of the carriage shaft.
The two stars are usually attached to each other on a so-called spider. The big one remains on the connecting rod itself. Unscrew them with the hex bolts.
This is how the system understands. Replacing and installing looks like the reverse process:
- Install the desired sprocket on the spider and tighten the fasteners. Change the large part together with the right connecting rod and screw the medium and small sprockets onto it.
- Next is the installation of the connecting rod on the carriage. Before this, it is advisable to clean and lubricate the carriage shaft.
- Carefully place the chain on the system and screw in the connecting rod by rotating the puller in the opposite direction.
- Tighten the fixing nuts and fit the plugs.
- Screw the pedal onto the connecting rod.
When replacing one star, it is advisable to clean the old ones. Lightly grease the system components before installing on the carriage.
So just replace the chainring. All of the listed tools are required. The connecting rod is a delicate thing, and a hammer and chisel is not the best option for removing it. The same goes for keys. It is difficult to replace them with pliers, besides, the nuts can easily “eat”. Well, without hexagons, it is impossible to disassemble the system into parts.
At the end, check the operation of the transmission. whether everything is in order and whether it is necessary to adjust the speed switch.
How to remove a sprocket from a bike
The sprockets of a speed bike are the main parts of the gearshift system that provide the gear ratio of the drivetrain. According to the degree of influence, they are divided into leaders and followers. The first are located at the connecting rod pair and are called the system. The driven ones are located on the rear wheel hub and are divided into cassettes and ratchets by design.
Over time, the stars wear out, as a result of which they need to be completely or partially replaced. The second option is more common in practice, since the wear is uneven. The most frequently used transmissions are subject to it. The problem, of course, requires a timely solution, otherwise driving will turn into torment. The chain will seize or skip over worn sprockets. Many modern models allow you to remove the sprocket and put it separately on the system or cassette without replacing the entire assembly. Read on how to do this.
Changing the sprocket on the rear cassette
The set of transmission stars of the rear wheel is several times larger than the front one. The standard kit includes eight components, and in high-speed models (or on a sports bike) there are 9 or 11.
It is worth mentioning right away that a cassette or ratchet can be placed behind. The cassette is a modern version with an internal splined mounting on the hub axle. Ratchets, as an outdated option, can only be found on a budget high-speed bike. The set usually includes 5-7 gears. External fastening, threaded, removable tool differs from cassette.
The fundamental difference from the cassette is its integrity. it is impossible to change the star separately on the ratchet. Here, either all at once, or nothing at all. Therefore, we will consider how to install a new sprocket on the cassette.
As with replacing the leading stars, special tools are required here:
- cassette remover;
- chain whip-retainer;
- adjustable wrench or head;
- optional: wrenches, chain release.
When removing the cassette, you will need to first remove the rear wheel from the bike and then the axle nuts. At the same time, when replacing the sprockets, you can also clean the chain. to remove it, you need a squeeze.
Sequence of work: 1. Remove the rear wheel with a 15 wrench, with eccentric fastening everything is simple. unclench the lever and loosen the fixing nut.
The next step is to unscrew the axle nuts. You will need a 17 key for it. To roll the mount off the rotating axis, we put on an additional nut to fix the axis.
Unscrew the bearing cone and pull out the bearing from the opposite side.
Remove axle with taper and bearing. About the bushing components: if necessary, you can immediately replace them with new ones.
Place the whip on the largest (lowest) star. We will rotate it clockwise.
Use an adjustable wrench or a head to turn the puller counterclockwise.
It is so easy to shoot a cassette at home. Most modern star sets are collapsible, you can install one or two new stars. However, in case of severe wear, when half of the cassette is worn off, it makes no sense to change them separately. Difficulties can also arise if the largest sprocket has been erased, on which all the others are usually attached.
Is it possible to dismantle a cassette without a puller and a whip? In principle, this can be done with a slotted tube and a spanner. The whip can be made by yourself by welding a piece of an old chain to the metal handle of the knife.
When replacing individual stars, especially the middle ones, we disassemble the cassette carefully so as not to lose all the spacer and fixing washers. Everything is easier with a cassette on a spider. it does not need to be disassembled, the star is removed separately from its mount.
Rear transmission assembly:
- Put and fix a new star, assemble a cassette.
- Using a puller, install the drum on the spline mount of the sleeve. Before tightening, it is necessary to align the drum so that the connection does not wear out under load. The whip is not needed here. just rotate the puller clockwise with effort.
- Assemble the bushing: insert the axle from the cassette side, then the bearing and the cone on the left side, fix the axle with nuts.
- Put on the chain and put on the rear wheel.
Check the operation of the transmission and adjust the rear derailleur. Timely replacement of sprockets will save you from unpleasant surprises on trips and will generally increase the resource of the bicycle transmission.
How to remove a cassette
Remove the bicycle wheel, then install the puller so that its splines fully enter the grooves of the retaining ring.
Place the whip on the sprocket so that the links of its chain sit tightly on its teeth. The whip handle should be to the right of the cassette and the chain on top.
Put the adjustable wrench on the cassette remover and turn it counterclockwise, while you need to hold the handle of the whip without letting the stars spin.
If the chain slips off, it is possible that the cassette stars are badly worn, or the whip is faulty. In this case, try to put it on a big star.
Unscrew the retaining ring to the end, then remove and unfold the stars and spacers. Lay out everything in order so that nothing is confused during assembly.
The cassette is removed, now it can be cleaned or changed.
How to install a cassette
When installing the cassette, the main thing is not to mix up the order of installing the parts. In order to correctly install the sprockets, they have grooves with different widths, and on the hub there are the same splines, thanks to them the teeth will stand in the right order.
Some cyclists advise to lubricate the hub surface before installing the cassette, but I think this will be superfluous. First, the chance of corrosion is too low. Second, the friction between the hub and the sprocket is also not high enough to cause damage. Thirdly, dust and sand can adhere to the lubricant, which can lead to accelerated wear of parts.
Apply grease only to the thread of the retaining ring, then it will be easier to unscrew it next time.
Put on the stars in turn, but do not forget about the spacer rings. In some cassettes, all or several stars can be connected into one non-collapsible unit. “spider”. But more often than not, all the stars go separately.
In some cassettes, to install the last asterisk, you must click on it. Check again if everything is installed correctly, with one hand press on the last sprocket, and with the other hand screw on the retaining ring.
Tighten the ring all the way, but do not tighten yet. Check again that all the stars are parallel to each other, and that they are straight. If something confuses you, disassemble the cassette and fix the problem.
If you are sure that everything is assembled correctly, then take the cassette remover and tighten the locking ring clockwise to the end.
Everything, the cassette is assembled. Once again, inspect the correct assembly and you can put the wheel in place.
How to remove connecting rods from a bike without a puller
Active cycling requires certain skills to quickly repair vehicles. Before going on a long trip, it is best to foresee possible breakdowns and malfunctions of equipment, take with you the necessary tools and a set of spare parts, for example, cameras. It often happens that the right thing was not at hand, but even then there is a way out of the situation. For example, if you need to adjust the carriage of a bicycle, then you need to remove and disassemble the connecting rod, but there is no tool. This problem has a solution and it is worth familiarizing yourself with the design and purpose of this part in more detail.
The device and purpose of the part
A bicycle connecting rod is a metal lever that has a large and a small head on the rod. This element is of several types:
- One-component. They represent a single design. left, right connecting rod, axle. The advantages of this type are great strength, easy maintenance, but they have a significant weight;
- Two-component. Here the drive sprocket, the right connecting rod and the axle are connected, and the left one is connected separately with a nut;
- Three-part. This most famous and popular system is the axle, the left connecting rod and the right one together with the sprocket.
How To Change Chainrings. Changing Your Chain Rings For Road Or Mountain Bikes
The load on the connecting rod is very high, and therefore they are most often made from solid steel, but there are also options from aluminum alloys, for example, in sports type bicycles or imported models. Inexpensive two-wheeled vehicles have a front sprocket block, combined with a connecting rod and non-separable. In this case, when replacing the sprockets, both connecting rods must be replaced. New ones are selected depending on the type of existing carriage.
This part of the bicycle can also have various types of fastening, for example, square, slot. The first is used in professional sports equipment models, and there is also the latest development. rotor system.
How to disassemble a connecting rod without a puller?
The simplest method is to use a special puller. If there is no such tool, then in order to disassemble, remove and repair it, you need to make some effort and skill. During the ride, dirt and dust gets into the attachment area of this element, the element literally sticks to its attachment due to heavy loads. In this case, you need to know how to remove the cranks from the bike without using a puller. You can fix the problem and make repairs on your own, and this will help you get to the place of equipment repair.
In unsuitable conditions, you can try the following methods in order to remove the part. If you unscrew the nut or bolt that secures the connecting rod and drive a certain distance, then the element can be disassembled and removed much easier, and in the future, replace or adjust what is required. The method is to pour boiling water over it. Consequently, all dirt and dust will get wet and making repairs to the bike, it will be easier to remove the element. This option is also suitable when it is important to remove the pedals. It is important to know and not to be confused in which direction which pedal is unscrewed. The left pedal has a left-hand thread, and the right one. respectively.
If the bottom bracket of the bike requires adjustment, the cranks must also be removed from the bike. Other recommendations will also help in case of unforeseen breakdowns. If the cable of the gearshift or brake is damaged, you need to replace it with a new one, and if there is none, then tie the torn ends. Failure of the bicycle spokes. this is also a common problem. Then a wire with a diameter of about 2 mm will help. The end of the spoke next to the rim is crocheted, and then a piece of wire is inserted, which must be passed through the socket of the hub. This replacement is far from perfect, but it will allow you to reach the goal and the place where you can repair the equipment well. Regular viewing and maintenance of two-wheeled vehicles will avoid many of these problems and make the trip enjoyable.