The bicycle is the most environmentally friendly and quite popular form of transport. Its main advantage is portability. But like other vehicles, a bicycle is subject to wear and tear on its component parts.
Weak tension
The bike chain will fly off mainly due to weak tension. On newer bike models equipped with a special tensioner, the pull-up process is automatic. True, the chain on such bicycles can fly off due to a malfunction of the shifting mechanism. Try changing the cable on the derailleur. If this does not help, replace the switch itself completely.
On older models, the chain is tensioned by hand. Unscrew the rear wheel and tighten it while adjusting the position of the wheel. It is not worth tightening too much, the chain may break during the operation of the bicycle. After completing this procedure, properly lubricate it. This will extend the life of the chain mechanism.
Rear wheel deformation
Another reason for the chain to fall off is the deformation of the rear wheel. Otherwise, an ordinary "eight". It also affects the handling of the vehicle and the braking performance. Especially such deformation has a detrimental effect on the braking mechanism of the rim type.
To somehow influence this situation, try tightening the knitting needles. They should be tightened until they are all equally taut. When properly adjusted, all spokes should make the same sound when struck. If this procedure does not help and the wheel rim does not straighten, then it is best to replace the wheel with a new one.
Curvature of the main link
The next reason, close to the previous one, is the deformation of the main link, which is located on the pedal. Remove the pedal and try to align it. To do this, lay it on a hard, preferably metal surface and hit the curvature with a hammer. The difficulty is that this link cannot be separated from the pedal. But this factor only complicates the recovery process, and does not make it impossible.
Malfunction in drum brakes
A malfunction in the drum brakes can be another cause of chain slack. It's all about the bearings located there. With heavy wear, the bike starts to "miss" and because of this, the chain endlessly falls off. To get rid of this problem, remove the rear wheel and unscrew the bottom bracket. To do this, unscrew the nut on one side and remove the corkscrew on the other. Then collect all the remnants of the old bearing and put in a new one. Before reinstalling the carriage, liberally lubricate the carriage and the inner drum of the wheel. Litol is very suitable as a lubricant. It retains its lubricating properties well for a long time, even with intensive vehicle use.
