What should I do if the bicycle brake is not working?

1. Brake pads too far from the rim

The adjustment method of the ordinary front brake is: use a wrench to loosen the brake nut, lift the front brake fork and the front pull tube up with the left hand, so that the distance between the brake skin and the rim is only 1 mm, and then use the right hand to put the handlebar on the front brake. Pull down the short tie rod, make the short tie rod and the front pull tube in a straight line, tighten the brake nut, and release the left hand, the brake shoe will drop by 1-2 mm, so that the brake shoe is about 3 mm away from the rim.

Method/Step 2:The adjustment method of the ordinary rear brake is: first loosen the clamping nut under the frame, and then tighten the adjusting nut. When the brake shoe is adjusted to about 3 mm from the rim, tighten the clamping nut. If the brake shoe is too close to the rim , the adjustment direction is opposite. If the brake plate, short tie rod, rear pull tube and other parts are loose, or the opening angle of the rear crank spring is too large, the brake screw can be loosened when the elasticity is small, and the rear pull tube can be lifted with the left hand to make the brake shoe face the rim Approach, and then use the right hand to pull down the short lever of the handlebar, so that the short lever and the rear pull tube are in a straight line, and then tighten the brake screw. The nut on the tie rod joint, pull the rear crank forward to make the rear brake skin and rear brake fork move forward, press the rear crank spring at the same time, and finally tighten the nut on the long tie rod joint

Method/Step 3:

2. Asymmetric left and right brake pads

When braking, the contact area between the brake pad and the rim on one side is large, and the contact area between the brake pad and the rim on the other side is small. The reason for this failure is:

(1) If the front wheel or rear wheel is not installed correctly, the front wheel or rear wheel should be installed so that the distance between the front rim and the left and right front fork legs is equal, so that the rear rim is made. The distance between the left and right flat fork legs is equal;

(2) The rim has axial flutter, and the axial flutter of the rim should be eliminated;

(3) If the gate plate is installed biased, the screws on the plywood should be loosened, the gate plate should be installed correctly, and the screws should be tightened;

(4) If the brake fork is deformed, you can use wire clamps to clamp the brake and turn the brake to correct the deformed brake fork. If the brake skin is outward, the brake fork can be pulled inward; otherwise, it can be pulled outward, and then adjust the position of the brake plate to make the left and right brake skins symmetrical.
Method/Step 4:
3. When braking, the brake pads contact the rim one after the other
The reasons for this failure and how to overcome it are:

(1) The brake fork is not installed correctly. When installing the front brake fork, loosen the brake screw and the screw that fastens the gate, install the gate and the front brake fork, and then tighten the screw. When installing the rear brake fork, loosen the splint screw and install the positive brake fork. If it still does not work, loosen the nut on the rear crank splint, turn the rear crank splint, and install the rear crank crank;

(2) If the brake fork is deformed, the brake fork should be corrected. If the brake shoe on the right side of the brake fork contacts the rim first, the straight part of the brake shoe can be pulled down to make the brake shoe leave the rim, or the left straight part can be pulled up to make The brake shoe is close to the rim; otherwise, the pull direction is opposite.
Precautions
Brakes are very important, pay attention to frequent inspection and maintenance