It is generally recommended to replace a motorcycle's tires under the following circumstances:
Tread Wear: Tires have tread wear indicators called "wear bars" that become visible as the tire wears down. Once the tread depth reaches the wear bars, it is a strong indication that the tire needs replacement.
Tread Depth: It is advisable to replace the tires when the tread depth falls below a certain level, which is typically 1/32 of an inch (0.8 mm) or less. In some regions, this is the legal limit for safe tire use.
Age: Regardless of tread wear, motorcycle tires have a limited lifespan due to aging and degradation of the rubber compound. As a general guideline, motorcycle tires should be replaced every 5 to 7 years, even if they have sufficient tread depth. However, it's important to check the manufacturer's recommendations and consult with a tire professional for specific guidance.
Damage: If a tire is damaged, such as having a puncture, cut, bulge, or severe cracking, it should be replaced. Such damage can compromise the tire's structural integrity and safety.
Uneven Wear: Uneven tire wear, such as cupping, scalloping, or feathering, can indicate issues with tire alignment, suspension, or other mechanical problems. If the wear is excessive or cannot be corrected, replacing the tires is advisable.
Remember to regularly inspect your motorcycle tires for signs of wear, maintain proper tire pressure, and consult your motorcycle's manual or a professional mechanic for specific recommendations based on your bike's make and model.