What is the abnormal sound of the bottom axle of a mountain bike?

1. If the crank or crankset is loose, use a rubber hammer to hammer it a few times, and then tighten the crank or crankset fixing screw.

2. The steel ball or ball block inside the central shaft is damaged, this must be replaced on the central shaft, and you don't use your hands because the strength of your hands is much smaller than that of your feet, and it will not shake it.

3. The shaft lacks oil or dust is serious, if it is a sealed integrated shaft, only a new one, you have no way to add oil or take it out for cleaning, if it is the old-fashioned split bead block shaft, you can consider removing it to refuel or clean, but this shaft is generally difficult to dismantle, quite a test of your skills, tools and character.

4. There is also a possibility, mostly seen in the old-fashioned bead block shaft, that is, the outer bead block of the shaft is loose, resulting in a large gap between the steel ball and the bead block, resulting in abnormal noise, this repair is simple, luck with an open wrench to tighten the bead block, if your bead block shape is more special, the wrench or something can not be used, a hammer and a chisel waiting, the chisel is put on the bead block, regardless of the left and right bead block, all hammer in the direction of the rear wheel, and the hammer is OK.

It is possible that the central shaft is slightly shorter.

Water ingress into debris. Or metal chips from bottom bez.

The screws are not tightened, causing the front and rear to loosen, and it does not sound when it is fast and stable, but there will be a ...... when the car is shaken to accelerateThank you.

I used to be like that.

Take it apart and wipe it down.

That's it. Which kind of problem does your question fall into, go to the store and see.

The most serious thing is to change the bottom bracket.

The bottom bracket bearing is broken, replace it. **Remove the screw in the middle of the crankset and see if it's a square hole orSplines, just buy a bottom bracket with the same specifications and replace it. There are special tools to disassemble the sliding block shaft, go to the car repair shop, it is best to buy a bearing-style central shaft, buy a Taiwanese one online (estimated to be out of Kunshan, China) is about 30 yuan, very easy to use.

Mountain bike. The central axis is commonly used in the following types:

1. Loose bead type. 2. Sealing square type. 3. Sealed spline type.

4. Sealed hollow type. Mountain Biking Tips:Freestyle pedaling letter mess method:

At present, some elite athletes mostly use the balanced freestyle pedaling method. This pedaling method is to rotate the foot in a circle, depending on the position, the ankle joint.

The angle also changes.

Freestyle pedals, in line with the principle of mechanics, the direction of force and the circular tangent formed when the pedal rotates.

consistently, the knee joint is reduced.

and the amplitude of movement of the thighs, which is conducive to increasing the frequency of pedaling and naturally passing through the critical zone.

Reduce dead spots. The thigh muscles can also be relatively relaxed. However, this pedaling method is more difficult to master.

Generally, there are several parts that have problems:

1. Chain abnormal noise: due to the lack of lubrication due to the dryness of the chain, too much adhered sediment will also produce abnormal noise, the chain is often beaten by the wind and rain outside, and it is necessary to regularly apply some lubricating oil to the chain to solve it.

2. Abnormal sound of flywheel chainring: the degree of occlusion between the flywheel chainring and the chain is directly related to the lubricant, and the chainring can be properly coated with some lubricating oil; In addition, the relaxation of the chainring will also cause a "click" abnormal sound, which should be solved by removing the tooth disc and reorganizing.

3. Abnormal sound of foot pedal: because the abnormal sound produced when the driver applies pressure to the foot pedal, most of it is caused by the loose or deformed foot pedal, and it is recommended to replace a new set of foot pedals to solve it.

In the case of a protective box with a chain (this type is usually without a transmission.)

For non-enclosed bicycles, it is necessary to remove the screws of the protective box, and the joint between the protective box and the fixed place has hand pliers according to the situation.

After correcting it, you can put on the screws.

Notes:

1. Be sure to add lubricating oil after each cleaning, wiping or solvent cleaning of the chain. (It is not recommended to use organic solvents to clean the chain) and make sure the chain is dry before lubricating it.

2. Penetrate the lubricating oil into the link part of the chain, and then let it become viscous or dry. This ensures that the parts of the chain that are prone to wear and tear can be reliably lubricated.

3. Confirm whether to use the right lubricating oil, you can pour some on your hands to test. A good lubricant may feel like water at first (penetrating) but over time it will become viscous or dry (long-lasting lubrication).

4. In order to avoid excessive lubricating oil accumulation and blockage, only oil the key parts of the chain. After oiling, it will reduce wear and noise during chain operation.

This is to find the problem, which are fault squeaks and which are reasonable squeaks. Only nearly 20% of the vehicles that went to the repair shop to detect abnormal noises really had problems. In the case of a turbocharged engine, there is a must be a difference between the sound and the sound of a naturally aspirated engine; Models with engine guards may also make noises due to friction; After some car owners come into contact with different cars, it is likely that due to their lack of understanding of mechanical knowledge, they mistake reasonable abnormal noise as a vehicle failure.

Therefore, learn to distinguish the abnormal noise of the car and avoid wasting time and energy.

How to identify the sound of a car:

In practice, due to the limitations of working conditions, the sound of the car can only be described and compared by judging the sound in daily life. For example, the "rattle" sound caused by the dry friction of the bearing, and the "click" sound similar to the small hammer hitting the cement floor caused by the excessive valve clearance.

1. Correctly distinguish between normal and abnormal sounds.

The vibration of each mechanism in the work of the car will emit a variety of sounds, but the sound does not mean that the car is faulty, in order to avoid unnecessary disassembly, we must first distinguish between normal sound and abnormal noise. The normal vibration sound of each system component (such as the noise on the surface of the engine), the impact sound of the gear when shifting, the air intake sound and exhaust sound of using gas as the working source, and the gear meshing noise are all normal sounds. Abnormal noise (abnormal noise) can be divided into slight noise, general noise and malignant noise according to the impact on the performance of the car.

Slight noise, such as the flashover sound of high-voltage electric leakage, the slight loose sound of rolling bearings, etc., the general volume is small, the degree of wear of the parts is not large, and there is no significant change for a long time, and this kind of fault can still maintain the normal operation of the car without repair.

3. When diagnosing abnormal noise, attention should be paid to creating good auscultation conditions and trying to eliminate the interference of other noises, so as not to affect the accuracy of judgment.

It is best to consciously amplify or reduce the sound, that is, use a screw or other metal rod as a stestological instrument to contact the sound part to amplify the sound, or use a single cylinder fire cut-off to reduce the sound to meet the diagnostic needs. The auscultation site should be kept quiet to minimize human interference.

1. The ordinary central axis kit is divided into "central axis, left bowl sedan chair Li Tan, right bowl, bead ring left and right" If you step on it, you will find that the central axis is a little shaky again, and it is uphill and "Kaka" sounds.

2. If the owner of the ordinary suite finds such a situation, Lima can solve this problem by changing the bead ring, because the quality of the bead ring is not good, there will be gaps due to excessive wear, resulting in such a problem, and if it is not replaced for a long time, it may cause damage to the entire kit.

3. The central shaft of the conjoined body is divided into "the central shaft, one on the left and one on the left and right of the bearing, the right bowl and the central shaft are integrated, and the left bowl" 2If it is an integrated bearing shaking and abnormal noise, it can only be solved by changing the whole kit.

If you find similar problems while riding, it is recommended to fix them as soon as possible, although it will not affect the ride, but it will be damaged by other parts.