Bicycle Crank Arm Keeps Coming Loose
Riding a bicycle is one of the best ways to stay fit and healthy. However, when the crank arm keeps coming loose, it can be frustrating and even dangerous. This problem is not uncommon, and there are many reasons why it happens. In this article, we will discuss the causes of the problem and the solutions to fix it.
What is a Bicycle Crank Arm?
The crank arm is the part of the bicycle that connects the pedal to the bottom bracket. It is responsible for transferring the power from the rider's leg to the bicycle's chain, which then propels the bicycle forward. The crank arm is made up of two parts, the crank arm itself and the bottom bracket spindle. The spindle fits into the bottom bracket, which is attached to the bicycle frame.
Why Does the Crank Arm Keep Coming Loose?
There are several reasons why the crank arm keeps coming loose. Some of the common reasons are:
1. Loose Bolts
If the bolts that hold the crank arm in place are loose, the crank arm will come loose. This can happen due to wear and tear or improper installation.
2. Worn Out Bottom Bracket
If the bottom bracket is worn out, it can cause the crank arm to come loose. This can happen due to wear and tear or improper installation.
3. Incorrect Installation
If the crank arm is not installed correctly, it can come loose. This can happen if the bottom bracket spindle is not properly aligned with the crank arm or if the bolts are not tightened to the correct torque.
4. Over-tightening
If the bolts that hold the crank arm in place are over-tightened, they can cause the crank arm to come loose. This can happen if the bolts are tightened beyond the recommended torque.
5. Crank Arm Damage
If the crank arm is damaged, it can cause the crank arm to come loose. This can happen due to wear and tear, impact, or improper installation.
How to Fix the Problem
The solution to the problem depends on the cause of the problem. Here are some solutions to fix the problem:
1. Tighten the Bolts
If the bolts that hold the crank arm in place are loose, tighten them to the recommended torque. Refer to the bicycle manufacturer's manual or consult a professional bicycle mechanic for the correct torque specification.
2. Replace the Bottom Bracket
If the bottom bracket is worn out, replace it with a new one. Refer to the bicycle manufacturer's manual or consult a professional bicycle mechanic for the correct replacement.
3. Re-install the Crank Arm
If the crank arm is not installed correctly, re-install it. Make sure the bottom bracket spindle is properly aligned with the crank arm and tighten the bolts to the recommended torque.
4. Loosen the Bolts
If the bolts that hold the crank arm in place are over-tightened, loosen them and then tighten them to the recommended torque.
5. Replace the Crank Arm
If the crank arm is damaged, replace it with a new one. Refer to the bicycle manufacturer's manual or consult a professional bicycle mechanic for the correct replacement.
Conclusion
The crank arm keeps coming loose is a common problem faced by many cyclists. The problem can be caused by loose bolts, worn-out bottom bracket, incorrect installation, over-tightening, or crank arm damage. The solution to the problem depends on the cause of the problem. Tightening the bolts, replacing the bottom bracket, re-installing the crank arm, loosening the bolts, or replacing the crank arm are some of the solutions to fix the problem. If you are not sure how to fix the problem, consult a professional bicycle mechanic for assistance.