For motorcycle riders, helmets are more basic and important protection. In case of a traffic accident, it can ensure that riders will not be seriously injured. However, in selecting and using helmets, several principles must be paid attention to, especially the expiration date. When the expiration date is exceeded, the protection ability will decline.

There are many precautions for purchase and use of helmets, especially the storage period.

Principles for helmet selection:

1. Helmets also have a shelf life: Do not choose helmets that are 4-6 years after the manufacturing date. Be sure to confirm the manufacturing date to avoid being cheated by the store or buying helmets that have exceeded the shelf life.

2. There must be conformity marks, including CNS, DOT, SNELL, ECE, R05, JIS and other marks.

Principles of helmet use:

1. Helmets should be replaced after 2-3 years of use. Each brand may be different, so you can ask the manufacturer.

2. Do not use helmets that have fallen heavily or had an accident. Even if they are only slightly scratched, their appearance remains intact, but the helmets may have small cracks, and the protection strength may also decline, which is hard to detect by the naked eye. It is recommended to replace them for safety.

The shelf life and manufacturing date are the key to selecting helmets. If it is too long, the protective ability will decline.

As for the reason for the replacement of the expired helmet, the main reason is that the interior materials of the helmet are all plastic PP, ABS and composite materials. After a long time of sun exposure, these materials will become brittle, which will lead to a decline in the protection ability. In case of an accident, the knight's head cannot be effectively protected.

When purchasing helmets, pay attention to whether there are conformity marks.