My bike shifts to the smallest teeth, and the chain jumps forward on its own!

This could be caused by the bike's chain being too loose or the rear derailleur not being properly adjusted. In bicycle shifting systems, the rear derailleur is used to control the position and movement of the chain on the flywheel. If the rear derailleur is not properly adjusted, the chain may jump or fall off on the smallest teeth.

You can try the following steps to fix the problem:

1.Check the tightness of the chain: suspend the rear wheel in the air, tighten the chain by hand, if the up and down swing range of the chain is between 2-8cm, it means that the chain tightness is appropriate. If the chain is too loose, consider replacing the chain or adjusting the rear derailleur.

2.Check the adjustment of the rear derailleur: On the smallest teeth, the rear derailleur should adjust the chain to the innermost gear.

If the rear derailleur is not adjusted properly, the chain may jump to other gears, causing the chain to jump. You can check your bike's manual or search the web for tutorials on how to adjust the rear derailleur.

If you have tried the above steps and still can't fix the problem, it is recommended to have a professional repair it.

There are several possibilities for this.

1 is that the tension spring of your rear derailleur is not adjusted well·· This results in too much clearance between the flywheel and the chain.

2 is that it is possible that your flywheel and chain are overworn.

As a result, I couldn't eat and live the flywheel for days.

The feeling of stepping on the air all the time.

3. It is possible that the wear of the flywheel and the chain are different.

As a result, the chain can't eat the flywheel.

Keep stepping on the air. If there are several possibilities, the first one is more likely.

It is recommended that LZ go to a professional car dealer and let a professional technician take a look.

If it's the first question, just tune it.

If there are two types left, it is estimated that the only thing to do is to replace the chain.

Or the flywheel.

What do you not understand hi me.

This is easy to do... Minor issues.

There are two possibilities for this.

1 The strength of the front pull cable is not adjusted properly.

2 l limit screws are too tight.

Solution: 1 There is a knob at the connection between the front dial or the front finger dial and the wire pipe Turn the pedal with the left hand Turn the knob with the right hand Turn the knob in which direction to twist yourself Try If you twist in one direction, the problem is getting more and more serious. . . Instructions should be twisted in the opposite direction.

2 There are two small screws on the front derailleur, find the one that says "L" in it, and loosen it a little with a Phillipsdriver.

It may be one of the ways to solve it, or it may be possible to continue to ask about both problems.

Summary. Two possibilities.

1. The bicycle transmission is not aligned. Just go to the bike shop and deal with it.

2. Your bike's shifting system is a high-end model from SHIMANO. Multi-Release is a Shimano patent that allows you to switch between two gears in one stroke (i.e. with a single press) to achieve the shortest possible time to switch to the best gear. This technology is available on Shimano's XTR, Saint, Deore XT, Alfine, R780.

If your bike isn't one of these configurations, it's most likely the former possibility – the shifting is going to be adjusted.

Beg. What to do if the transmission presses on the two chains after the bike shifts.

Two possibilities. 1. The bicycle transmission is not aligned. Just go to the bike shop and deal with it.

2. Your bike's shifting system is Shimano's high-end model. Multi-Release is a Shimano patent that allows you to switch between two gears in one stroke (i.e. with a single press) to achieve the shortest possible time to switch to the best gear. This technology is available on Shimano's XTR, Saint, Deore XT, Alfine, R780.

If your bike isn't one of these configurations, it's most likely the former possibility – shifting is going to be slower. Ask Caisen to close.

Hope mine is helpful to you.

The mountain bike chain hits the front crankset on the transmission, the solution:

1. If the front derailleur (the transmission of the front crankset) near the side of the frame touches the chain, it is caused by the chain being too tight. You can adjust the fine adjustment screws on the left handlebar. Rotate the trimmer screw clockwise to observe the gap between the chain and the derailleur plate, and the adjustment can be completed when the gap reaches about 1 mm.

2. If the front derailleur (the transmission of the front crankset) is far away from the frame and the derailleur plate touches the chain, it is caused by the chain being too loose. You can adjust the fine adjustment screws on the left handlebar. Rotate the trimmer screw counterclockwise to observe the gap between the chain and the derailleur plate, and the adjustment can be completed when the gap reaches about 1 mm.

This is the role of the flywheel behind the self-owned brother Huiwei's car, and the following will talk about the flywheel.

First of all, let's talk about the structure of the flywheel: the flywheel is fixed at the right end of the rear axle with internal thread screwing, maintains the same plane with the sprocket, and is connected with the sprocket through the chain to form the driving system of the bicycle. In terms of structure, it can be divided into two categories: single-stage flywheel and multi-stage flywheel.

The single-stage flywheel, also known as the single-chain wheel flywheel, is mainly composed of parts, such as jackets, flat blocks and cores, thousands of envy peijin, jack springs, washers, wire blocks, and steel balls. The multi-stage flywheel is based on the single-stage flywheel, adding several flywheel pieces, combined with the sprocket on the central axle, to form a variety of different transfer ratios, thus changing the speed of the bicycle.

Let's talk about the working principle of the flywheel: when the pedal is stepped forward, the chain drives the flywheel to rotate forward, at this time, the flywheel internal tooth and the jack are contained, and the rotating force of the flywheel is transmitted to the core through the jack, and the core drives the rear axle and the rear wheel to rotate, and the bicycle moves forward. When the pedal is stopped, the chain and the jacket do not rotate, but the rear wheel still drives the core and the jack to rotate forward under the action of inertia, and the flywheel inner tooth produces relative sliding, thereby compressing the core into the notch of the core, and the jack compresses the jack spring.

When the jack tooth top slides to the top of the flywheel's inner teeth, the jack spring is compressed the most, and then slides forward a little, and the jack is bounced to the tooth root by the jack spring, making a "click" sound. The core rotated faster, and the jacks quickly slid on the inner teeth of each flywheel, making a "click" sound. When the pedal is reversed, the jacket rotates in reverse, which will accelerate the sliding of the jack, making the "click" sound more urgent.

If the chain moves in the forward direction, the chain will generally not fall. If it is reversed, the chain may be dropped.

Bicycle shifting is achieved by changing the size of the wheel wheel by the transmission.

In normal riding conditions, the chain is moved from ** to the small disc, or from the small disc to ** through the transmission, this speed change requires a process, that is, the chain needs to run for no less than half the circumference length of the wheel disc to be completed. This is also the reason why the chain does not drop when shifting gears during normal riding.

When stationary, the chain does not move, and the transmission is adjusted directly, which actually only completes half of the shift, that is, only moves the chain away from the original wheel, and does not really fall on the shifting target wheel. The chain moves in the forward direction and continues the process of shifting, on the contrary, there is no ***.

The 3rd gear off the chain is generally that the limit screw is not adjusted well, adjust the h limit screw, according to what you said, it should be, adjust clockwise.

The rear speed can not be adjusted to the gear, it is estimated that it has a little to do with the rear dial deformation you said, you can use your hand to break the rear dial to see if it can be corrected, if not, you can only find you to buy the store's after-sales service, see how this thing is solved.

Transmission fine-tuning, adjustment of limit screws.

The two screws are lowered and then tightened at a constant speed.

It may be that the transmission transmission distance is not right, and it would be good to have a picture.

If the chain only jumps when the chain is hung and flies at the minimum, it must be caused by the sharpening of the teeth. If the chain hangs other flies, there are also skipping chains or the dialback is not smooth or can not be dialed back, etc., it means that there is also a problem with the tension of the rear dial cable.

However, judging from the **, it is necessary to change the back flight. Even if it can last for a while, it won't be too long. Moreover, it is the maximum power provided by the minimum fly, and the minimum flying card teeth are sharpened, and the loss of power is still very large.

Another point that can be seen from ** is that your car doesn't seem to be maintained very often. The chain and flywheel are too dirty, and the chain needs to be washed and the flywheel (front and back) cleaned. The only place where the transmission kit really needs to be oiled and lubricated is the gap between each bend point on the chain, and the other parts should not get oil on the flywheel.

Quality issues and normal wear and tear aside, this is also the number one factor that accelerates the wear of your flywheel!

In addition, do not use the combination of front and middle fly + rear fly for a long time, the tilt angle of the chain is too large, which will accelerate the wear of the flywheel and the chain.

Yes, go to the bike shop and do the repairs.