In fact, most people still do not pay enough attention to bicycle helmets. How important is it to wear a helmet on a bicycle? It is a life-saving thing at the critical moment. The structure of the bicycle helmet is very simple. According to the processing method of the shell (PC or PVC) and EPS (Expanded Polystyrene), it can be divided into an in-mold helmet and an out-mold, and the foam layer is a core component which can cushion/absorb external impact energy when the rider suffers an accident. One principle of the helmet to protect the head from injury is that when you are hit by a frontal or side impact, the helmet is the first to help you block most of the impact. The final result is that the helmet ruptures and the head will not be hurt or damaged, which can greatly reduce the degree of damage.
(1) Appearance design
The appearance of half-face bicycle helmets can be roughly divided into 3 categories:
Road bicycle helmet
Mountain bicycle helmet
Road bicycle helmets usually do not have a brim. The overall design is streamlined. The high-end road bike helmets are lightweight. So road bicycle helmets are naturally more suitable for people usually use road bicycles.
Mountain bicycle helmets often have a detachable brim, because the usage scenario may involve the outskirts and jungles, the brim can block the small branches that fall accidentally and prevent some rain. Some mountain bicycle helmets are more bulky than road bicycle helmets, and the number of ventilation holes is also designed to be less, but the overall coverage will be stronger.
The commuting bicycle helmet looks a bit like some electric vehicle helmets, with a more rounded shape, fewer ventilation holes, and a larger covering area for the head.
(2) Forming structure
There are two main types of bicycle helmets: in-mold helmet and out mold helmet.
In short, the in-mold helmet is manufactured by adopting the method of one-time stamping the blister PC shell and EPS into the mold. So the shell and the EPS are a whole without gaps. Whereas the out mold helmet is manufactured by adopting the method of combining the formed EPS and the PVC shell by handmade glue, so a clear gap can be seen between the shell and the EPS.