If you are experiencing an abnormal noise coming from the rear wheel of your N70, there are a few things you can check to determine the cause of the issue. Firstly, you should judge whether the noise is caused by tire noise or insufficient tire pressure. If the tire pressure is low, inflate the tire to the recommended pressure level. If the tire noise is the issue, you may need to replace the tire.

Another thing to check is whether the rear wheel is interfering with the mudguard. If there is friction, adjust the rear mudguard. However, be careful not to adjust the mudguard too high as this could prevent the folding hook from being stuck.

If the above steps do not resolve the issue, you may need to remove the rear wheel and add grease. This can help to reduce any friction and eliminate the abnormal noise.

If you are still experiencing issues after trying these steps, it is recommended that you contact our customer support team for further assistance. They will be able to provide you with additional troubleshooting steps or arrange for a professional repair if necessary.