Helmet Construction

Since bicycle was invented, it has gradually become a better vehicle for walking and leisure. Especially after bicycle sport has become a competitive sport, people are more fond of it. However, as a sport that wins by speed, safety has become an important issue. So people think of helmet. The emergence of bicycle helmet not only ensures the safety of cyclists, but also improves the performance of racing athletes. As early as the 1980s, some club riders first discovered the benefits of using helmet. Later, with the increase of hard asphalt roads and stone roads, more head injuries occurred while riding bicycles. Wooden pith helmet came into being.

Wood pulp is a cushioning material that absorbs impact force. But the helmet soon gave way to a fillable leather design that lasted until the 1970s. The helmet was originally called a hairnet because it had long, padded leather sheaths like a net over its head. This helmet is very attractive, with soft and high-quality leather foam. Although the helmet does protect the injured cyclist's ears from being rubbed or bruised by the ground. Unfortunately, its anti-collision performance is poor.

The soft helmet is an important development. The helmet looks a bit like a bowl with a vent hole. The helmet is made of polystyrene, wrapped with synthetic elastic fiber (LYCRA), and then foam pad is added to the inside side.

The crashworthiness standard of bicycle helmet and the strength of buckle were put forward by CPSC in the mid 1970s. Such or other project parameters are proposed according to different institutions, such as the SNELL Foundation, the National Bureau of Standards and the American Institute of Testing Materials. At that time, only one light motorcycle helmet met this standard. However, cyclists refuse to wear the helmet because it is heavy and airtight.

To this end, BeLL Biker company first developed a bicycle helmet that meets the CPSC standard. It is made of ABS plastic and wrapped with polystyrene foam. Later, the newer shell material PVC and the higher price material polycarbonate greatly reduced the weight of the helmet. Generally speaking, bicycle helmet can withstand at least two crashes, the first is when it collides with other cyclists or bicycles, the second is when the cyclist falls to the ground himself, and these materials have a good cushioning effect on both crashes.

Since the appearance of bicycle helmet, its shape has changed a lot. The circular helmet has long been obsolete, the edge of the helmet has become smaller, and the air vent has changed a lot. It really has the effect of cooling and breathing, and also conforms to the principle of aerodynamics. For example, at an international bicycle exhibition in 2013, there were as many as 37 holes in the LMARF 111 bicycle helmet. Before that, there were up to 23 helmet holes. In addition to road bicycle helmet, with the emergence of mountain bike movement, its helmet also appeared. For example, BELL X-RAY is larger and less aerodynamic than highway helmet. The main function of these helmet is to make sweat evaporate at low speed in hot climate.

Finally, the principle of helmet protection is that the wearer can make the head stopped relatively slowly, while the non-wearer often causes brain edema and hemorrhage when hitting the head on the ground. The aggregated spheres in the helmet absorb the impact force and avoid these unfortunate events.

The special helmet for riding is generally composed of seven parts:

Cap case: Hard case on the outermost layer of helmet. If an accidental collision occurs, the cap shell is the first line of defense to protect the head and is used to disperse the impact force.            

Cap body: it is the foam inner layer of the helmet. It's the second line of defense to protect the head. It is mainly used to absorb the impact impulse in the accident and reduce the accident injury.

Buckle and Hat Belt (Safety Belt): Used to fix the helmet position. The cap band is fixed below the ears on both sides, and the buckle is fixed at the throat. Note: After the buckle is fastened, the buckle and throat should reserve 1 to 2 fingers of space, remember not to be too tight or too loose.

Cap eaves: Cap eaves are divided into two types: fixed and adjustable. Generally, the helmet for road bicycle riding has no eaves. The function of the eaves is to avoid foreign objects flying into the eyes of the rider, and at the same time to play a certain shading effect.

Stomata: Stomata is designed to help the head heat and ventilate, to ensure that the hair is dry during long-distance riding. The more air holes, the cooler the rider will feel, but the lower the relative safety factor. Helmets with appropriate stomata are generally preferred.

Knob: There is a knob behind the helmet to adjust the tightness. The rider can adjust the helmet size according to the size of his head.

Padding: Padding can absorb sweat and micro-vibration from human body during riding.