market dynamics
How to prevent motorcycle clutch failure?
Release date:2019.12.03

Analyze the causes of clutch failures first

The cause of not being able to go into gear

1. The fork is broken or deformed

2. Gear hook or gear shift shaft assembly is broken or deformed

Cause of difficulty in shifting gears

1. Clutch separation is not complete

2. Uncoordinated shift operation

3. Gear hook is worn or off

4. Gear shift cylindrical CAM groove or pin wear

Cause of automatic loss of gear

1. Gear contact claw or hole wear

2. Insufficient spring force of limit block

3. Wear of variable speed cylindrical CAM and fork

Cause of clutch slip

1. Improper adjustment or damage of clutch control system

2. Wear or damage of friction plate

3. The spring loses its elasticity or its size is shortened

Cause of incomplete clutch disengagement

1. Separate trips are not appropriate

2. The thickness of friction plate is not suitable

3. Uneven spring elasticity


Determine the degree of clutch wear

1. Under the condition that the engine speed remains unchanged, the driving speed is obviously lower than before;

2. When driving, the engine speed increases, but the speed change is not obvious;

3. Put up the main support, let the rear wheel leave the ground, hang 1 gear, keep the small throttle, slowly step on the rear brake pedal, obviously feel the rear wheel start braking, but the engine speed does not significantly reduce;

4, judging by the color of the oil: when changing the oil, there is a little gray material on the black oil, can be judged to be clutch wear. If the clutch ablation is serious, the oil is black gray mixture;

5, through the oil taste judgment: after the engine overheating, the abnormal smell of coke, when changing the oil, the oil has a clear smell of coke.

Repair the clutch

Almost all motorcycles are equipped with clutch grips at the left handlebars to separate and engage the clutch, so that the transmission system and the engine can be connected and separated easily. In use, if the clutch failure, it will make the motorcycle can not run normally, therefore, should strengthen the inspection and maintenance of the clutch.

Check if the clutch is working properly

1. Gently grasp the clutch grip with the middle finger and forefinger, check and adjust the clearance. Handle end travel should be 15-20mm and root should be 3mm. If the gap is too large, the clutch will not be separated completely; If the clearance is too small, it will cause the clutch to slip. Clutch clearance size is different for different models, so it should be adjusted according to the specific requirements of the operation manual, and the minimum travel distance of the grip end should be 10mm.

2, clutch grip is heavy, as important as the gap. Heavy handling is often caused by cable damage or lack of grease on the cable, the latter is more common. The way to judge whether the clutch grip is heavy is to use the spring to pull the clutch handle. The tension is within the range of 50-60n, which is normal. If more than 68.8n, the grip is heavy. If necessary, the pull wire can be replaced, if there is still a heavy feeling after the replacement of the pull wire, it should be further found out the reason, to exclude.

3. Change the gear position through the pedal, increase the engine speed slightly at the same time, and then brake the rear wheel with the foot. At this time, slowly release the clutch handle, if the engine flameout, it indicates that the clutch technical state is normal (not skidding); If the engine speed decreases, but does not shut off, then the clutch slip, should be maintained.

4. Check whether the clutch release is complete: lift the ladder, unscrew the clutch grip and conduct the gear shift test. If the grip is tightened and the gear strikes while shifting, the clutch is not completely separated.

5, check the clutch grip to the transmission of the pull line is normal: if found its plastic foreskin appeared cracks, can be wrapped with plastic tape, in order to waterproof immersion. The cable damage is related to the technical condition of the motorcycle itself, so the whole motorcycle should be well maintained.

Adjust the clutch with problems in each link

1. Adjust the clutch grip stroke

If the travel of the clutch end does not meet the requirements, you can loosen the locking nut at the root of the grip, and rotate the adjusting nut left and right so that the travel of the grip end is 15mm-20mm. If the cable is changed, attention should be paid to the different direction of the cable of various models. After the cable is installed, the handlebars should be hit to the leftmost and rightmost respectively to adjust the free travel of the grip.

2. Adjust the clutch clearance

Generally, it is ok to turn the adjusting nut of the grip, and it will be better to check and adjust the cable at the same time. If the clutch grip is adjusted, the clearance is still not up to the requirements should be removed the pull wire, through the nut cap adjustment, if the pull wire skin crack, bend deformation, should be replaced with a new pull wire.

3. Maintenance of clutch slip

Clutch slippage is mainly caused by insufficient clutch grip clearance. Right grip clearance is too small or there is no clearance, the clutch is always in the semi-clutch state, the result is bound to cause clutch slip. You can loosen the lock nut at the base of the grip counterclockwise and then adjust the nut left and right until the clearance is suitable. If the clearance standard value cannot be reached after adjusting the grip nut, the support for fixing the pull wire adjusting nut should be lifted up. After the adjustment, start the engine, check whether the gear shift is smooth, neat, there is no grinding or abnormal noise. If there is a problem, it should be further examined to find out the cause and eliminate it.

Tools and techniques used

Using a box wrench and screwdriver, secure the screw and unscrew the lock nut counterclockwise. Then, use the wrench to jam the loose lock nut and make the clutch grip end travel within 15-20mm. Turn the wrench right and tighten the lock nut.

Generally by adjusting the clutch grip and pull wire, the clutch clearance can meet the technical requirements. However, for heavy handling caused by fatigue deformation, crack of outer skin, and bending damage, the best solution is to replace the cable. After the adjustment, should start the engine for testing, see whether the clutch is skidding or separated from the phenomenon, if there is, should be readjusted.