Bicycle Rear Hub Maintenance
If you ignore the need for periodic maintenance of the rear hub of a bicycle, then the life of the “iron friend” can be greatly reduced. Experienced cyclists know what signs will indicate to disassemble / lubricate / reassemble the rear hub immediately. This process is not difficult, but you need to do everything in a certain sequence.
Typically, the hub body is the wheel hub. It has flanges on which the spokes are attached, and due to the presence of a set of sprockets on the rear wheel, the spokes have a slightly shorter length on one side. In bushings with loose bearings, the inner surface has tracks along which the balls move.
How to fix/ tighten a wobbly loose rear BMX bike wheel / hub
How to properly fit the rear wheel of a bike
The eccentric mechanism uses a hollow hub axle to secure the wheel axles, equipped with a shaft, a lever that acts as a cam mechanism, and an adjusting nut. The cam exerts tension on the shaft and pulls, and the adjusting nut is pressed firmly against the pad on the frame. This tension holds the wheel securely to the frame.
The adjusting nut determines the amount of tension on the cam lever to secure the wheel axles and cam. Lubricate the cam mechanism if it is sticky or dry.
The eccentric mechanism for securing the axles of the wheels is equipped with two conical springs. The small end of the spring faces the axis and the large end faces outward. These springs make it easier to fit the wheel. If one or both springs are twisted or damaged, they can be removed. They don’t matter as long as the wheel is firmly attached to the bike.
The so-called “open cam” may require more tension. These levers have a cam mechanism and must be lubricated frequently.
The wheels must be properly fitted to the bike frame. Misalignment can lead to problems with shifting and adjusting the bike. If the wheel is not securely fixed, it can fall off during the ride and injure the cyclist.
Rigid axle bushings use axle nuts on the outside of the frame plate. The axle nut contains a washer built into the axle nut, or a separate washer. If the washer has teeth or knurls, then they are connected to the recess to secure the wheel. Lubricate the threads on the axle when the wheel is mounted on the bike.
It is often easier to mount the front wheel when the bike is on the ground. When placing the bike on the ground, the axle must be completely in the pad on the frame.
Make sure that the cam lever for locking the axles of the wheels is in the open position and that its brakes are open.
Place the wheel in the pad on the frame. Make sure the hub is fully seated in the frame or fork.
- On the rear wheel, first turn the gear back and place the smallest gear between the top and bottom of the chain. Place the wheel between the brake pads, hooking the smallest gear on the chain.
- Cam mechanism for securing the axles of the wheels: tighten the axle so that the lever meets resistance 90 ° from the frame or fork.
- Straight axle: move the axle in place and turn clockwise until it stops.
- Solid axle: tighten both nuts on the axle until they stop.
- The use of a torque wrench is recommended. However, if it is not available, an effort must be made. For 25 Nm, apply about 40 pounds of pressure to the end of a 5 “wrench.
Determine the end position of the lever closing. Rotate the front arm and adjusting nut so that the arm ends up just at the front of the fork. Place the rear arm between the chain support and the seat. Reposition the lever as needed if it is not fully closed.
Re-remove the brake mechanism if applicable.
Make sure the wheel is in the center of the frame or fork. Loosen the nuts on the axle and, if necessary, adjust the center of the wheel in the frame and retighten.
Make sure the brake pad rim is centered on the wheel and adjust as needed.
To maintain the good condition of the mechanisms of the bicycle, it is required to periodically service it. For the rear wheel, similar work is done as follows:
- the body is tightened;
- defective bearings are replaced;
- mechanisms are lubricated;
- brake pads are adjustable.
How to Center Your Back Wheel EASY. BMX HACK
Despite its unpretentiousness, the rear wheel, with prolonged use without proper maintenance, will become unusable, which will require its repair. In addition, the rear wheel must be constantly adjusted to make the ride comfortable.
Replacing the bike camera
To remove the tire and remove the damaged chamber, it is necessary to remove the remaining air: the cap is unscrewed and the wheel is lowered by continuous pressing on the nipple. If there is no air in the tire, which is more often the case with punctures, then simply unscrew the cap.
To remove the tire, you need special paddles. Of course, you can pry the camera with an ordinary screwdriver and even a knife, but it is better to have a professional tool. With the help of assemblies, the tire is pushed on from the side opposite to the nipple. As soon as it starts to tighten, you need to pry the sides a little further, until a sufficiently free part of the tire is formed, and it can be safely pulled off the rim.
You need to tighten it very carefully so as not to damage the rim, you should not use too much force. When the tire is removed, remove the damaged camera and install a new one. The nipple is threaded into the hole in the rim, then the chamber is evenly distributed around the circumference.
Attention! The camera must lie flat, without kinks, otherwise you will have to reinstall it. There must be a flipper at the bottom of the rim to protect it from the spokes. If it is torn, you need to install a new one or get by with two layers of thin electrical tape.
From above, the outer part of the tire is put on the rim, this time from the side of the nipple. When installing the tire, the correct direction of the tread pattern must be taken into account. Usually, arrows are drawn on the tires, and in the upside down state of the bike, the forward direction is backward in the lower position. However, the rear wheel of a speed mountain bike is easy to go wrong, thanks to the cassette on the side. After mounting, the camera is inflated.
Replacing the camera
First of all, you need to lower the wheel. unscrew the cap and release the air by pressing the nipple. If the chamber is damaged and there is no air in it, simply remove the cap. To remove the tire, you will need mounting paddles, with which it will be convenient to pry on the tube until it becomes easy to pull it off the rim.
The camera can be replaced without the need for tools. First, the nipple is inserted into the hole in the rim, after which the tire is evenly put on the rim. Finally, the camera needs to be pumped up to the desired state.
Removing the cassette and bulkhead bushing
A hub is one part of a bicycle wheel that requires periodic maintenance. On average, you need to look into it once every 2000 km of run, in terms of time it is 2-3 months of active driving. If the wheel is already squeaking and there is a decrease in the efficiency of rotation, in other words, the great rides worse, then it’s time to remove it and inspect the hub.
The main problems with the bushing are backlash and insufficient lubrication of the bearings. Due to a violation of the fit or increased friction, the parts begin to wear out rapidly. If the wheel has not been serviced for a long time, the bearings may crumble altogether. To gain access to the bearings of the hub, you will need to temporarily get rid of the rear sprockets.
The reverse gear is removed using a puller and a so-called whip. Removing the cassette is a short-lived affair, but it will take a lot of effort to unscrew it from the wheel. In stages it looks like this:
- The stripper is inserted into the cassette nut.
- The whip holds the large star of the system so that it does not turn.
- With a wrench, the puller rotates, unscrewing the slotted nut.
- We remove the small stars that are installed on top, carefully fold them to the side along with the washers, and then remove the cassette itself.
Before disassembling the hub, you should slightly loosen the spoke tension. This can be done using a round key with knocked out holes for different diameters of the knitting needles. You need to loosen a little, a quarter of a revolution is enough. If the sleeve needs to be replaced, the spokes must be unscrewed enough to easily pull it out of the engagement.
A complete bushing replacement is required if both the axle and the bearings become unusable. However, often when the bushing is jammed, the axle is in normal condition, it is enough to change the bearings. Often, both will still serve faithfully if they are well lubricated. Proper lubrication will prevent parts from wear under dynamic loads.
The bulkhead of the axle part of the wheel is associated with cleaning the axle and bearing balls from dirt. The removed parts must be temporarily placed in a solvent, then allowed to dry, lubricated and reinstalled. Bearings in a skewed position must be adjusted by returning them to a straight position. However, during the backlash, the parts are already faulty, so replacement is the best option.
Rear wheel hub repair. Step-by-step instruction
Most often, the repair of the rear wheel hub is necessary either with backlash or when tightening the cone. So, step by step instructions:
- Checking the workplace. We clean the workplace of unnecessary tools, things that are not useful to you.
- Loosen the lock nut with a wrench.
- Loosen or tighten the flare nut.
- Tighten the locknut into place.
Fix Rear Bike Wheel. Off Center/Rubbing Frame
If the cause of the breakdown is a malfunction or breakdown of any part, then you should simply replace it using the following recommendations:
- After checking the workplace, remove the retaining ring.
- Remove the hub axle. First, remove all the parts that are on the opposite side of the sprockets.
- Checking the details for a malfunction.
- We replace the broken part.
- We put all the parts in place, tighten the flare nuts and locknut.
The lacing is the order in which the hub, rim and spokes are locked. It can be radial or cross. Radial provides for the installation of the hub without crossing the spokes with each other. Crossing the needles occurs.
Before disassembling the rear wheel of a bicycle, installing it on a special stand, or any other component of the vehicle, it is necessary to study its structure.
- knitting needles;
- tube or tire that must have the correct pressure.
The device of the rear wheel hub of a bicycle is quite simple: it is attached to the rim with spokes (from 12 to 48 pieces).
Wheel size is determined by the outer diameter, which ranges from 14 to 29 inches. Mountain bike models are more often equipped with 26-inch wheels, while hybrid or touring models are equipped with 28-inch wheels.
The rear wheel of a speed bike is not spoked. Instead, a solid disc is used for increased rigidity. This design is less resistant to oncoming air flow, but has increased windage, which makes it difficult to ride in a crosswind.
The life of a wheel depends on the design of the rim, and its strength affects the speed and safety of the ride. Modern bicycles are most often equipped with rims that resemble a box in cross-section. Thanks to this shape, the wheel is protected from damage when hitting a hard obstacle.
Steel or aluminum alloys are most often used as a material for the manufacture of rims. Steel rims are cheaper, but they are heavier and less resistant to corrosion. Carbon is considered the most modern material, but the price of such models is very high.
DIY bike rear hub repair
One of the most practical and healthy means of transport is the bicycle. However, its maintenance can cost you a pretty penny if you do not know how to repair at least minor breakdowns.
In such cases, it is simply necessary to have such skills as attention to detail and accuracy, since they will help you to repair or disassemble any part, for example, the rear hub of a bicycle wheel.