When it comes to mountain biking, there are a few things that are essential. A good bike, the right gear, and plenty of determination. One piece of...
Various types of bicycle helmets and safety analysis
Since the invention of the bicycle, it has gradually become a better tool for people to get around and relax, especially after cycling has become a competitive sport, people love it even more. But as a speed to win the sport, safety has become an important issue. So, people thought of helmets. The emergence of bicycle helmets not only to protect the safety of cyclists, but also to improve the performance of racing athletes. As early as the 1880s some club riders on high wheels first discovered the benefits of using helmets, and later, with the increase in hard tarmac and rocky roads and the increase in head injuries while riding bicycles, helmets made of wood pith came into being.
Wood pith was a cushioning material capable of absorbing impacts, but this helmet soon gave way to a pliable leather face design that lasted until the 1970s. This helmet was originally called a "hairnet" because it had a strip of padded long leather covering, like a net over the head. This helmet is very attractive, which has soft, high-quality leather wrapped in foam padding. Although this helmet can really protect the fall of the cyclist's ears from the ground rubbing or bruising. But unfortunately, it has poor impact protection.
An important development was the soft helmet, which looked a bit like a bowl with ventilation holes. This helmet was made of polystyrene, wrapped with synthetic elastomeric material (LYCRA), and later a foam pad was added to the inside.
The impact resistance standards for bicycle helmets and the firmness of the buckle straps were both proposed by the U.S. Consumer Product Safety Commission (CPSC) in the mid-1970s. The parameters for one item or another were proposed by various agencies, such as the SNELL Foundation, the American National Bureau of Standards and the American Society for Testing and Materials. At that time, there was only one light motorcycle helmet that met this standard. However, bikers refused to wear such helmets because they were heavy and not breathable.
For this reason, BeLL Biker first developed a bicycle helmet that met the CPSC standard, which was made of ABS plastic for the shell, wrapped in polystyrene foam. Later updated shell material PVC and higher-priced material polycarbonate greatly reduced the weight of the helmet. Generally speaking, bicycle helmets should be able to withstand at least two impact processes, the first is and other cyclists or car collision, the second is the cyclist himself fell to the ground, and these materials have a good cushioning effect on both impacts.
Since the advent of the bicycle helmet, many changes have occurred in its shape. Round helmets have long been obsolete, and now helmets have become smaller along the edges, and the ventilation holes have changed considerably, making them truly cool and breathable, and also aerodynamic. This year's Limar F111 bicycle helmet exhibited at an international cycling exhibition had 37 gaps, compared to 23 last year, when the most air holes in a helmet were only 23. In addition to road bike helmets, with the emergence of the mountain bike movement, its helmets have also emerged immediately. Such as BELL X-RAY, its size is larger, and road-type helmets are less in line with aerodynamic and other principles, the main function of these helmets is to allow sweat to evaporate at a low rate in hot climates.
Like today's COOLMAX LINERS helmets, these helmets are almost multifunctional because it also helps to absorb moisture. In general, most helmets don't do much when an athlete falls backwards. This has attracted the attention of helmet manufacturers, and for this reason GIRO has developed a positioning system to ensure that the back of the head is tightly fastened in the helmet. Such as ROCLOC type helmet with teeth buckle belt is the company's innovation, the company also used 10 kinds of position to adjust the helmet to ensure the suitability of the helmet.
The SPORTSCOPE helmet is a change from the common system style, introduced with six pieces of strong, flexible nylon mesh material patchwork, each into a single block of material can be changed according to the user's requirements. This helmet excludes the need for padding, and can reduce the distance between the helmet and the head. The function of bicycle helmets to protect the lives of cyclists is indisputable. According to the U.S. highway safety insurance study report shows: the number of cycling deaths in the United States in 1999, 98\% did not wear a helmet, while in the crash wearing a helmet people make them serious head injury risk factor reduced by 85\%, in addition with a helmet not only make people feel cool, and really cool. At the same time, the ventilation holes on the helmet can make the head feel cooler. To use an old saying, a clear head is more likely to win the race.
Finally, add a helmet to protect the principle of the head is to wear a helmet can make the head hit relatively slow to stop, while those who do not wear a helmet if the ground impact on the head, often make the brain edema caused by bleeding, while the helmet in the polymer of the ball can absorb the impact, to avoid these unfortunate events.
Can bicycle helmets prevent brain injury?
A new controversial study recently published by an Australian cyclist action group reports that bicycle helmets do not prevent serious brain injury and that there is no scientific evidence to support the mandatory application of such helmets. (Accid Anal Prev 2003, 35??287)
Curnow, chairman of the Australian Cyclists' Rights Action Group, said their findings, which were based on a comprehensive analysis of the results of 16 trials published between 1987 and 1998, called into question the mandatory application of bicycle helmets by Australian police. Another study completed by researchers from the Australian Transport Safety Bureau also showed that helmets do not prevent serious brain injuries.
While helmets can reduce minor head injuries, they do not prevent serious brain damage, Curnow said. The Canberra group leader said he did not deny that helmets help prevent scalp injuries such as scalp abrasions and lacerations; helmets with hard shells can prevent skull damage, which can help prevent brain damage. But most helmets currently in use are soft shells, making their ability to prevent head injuries problematic.
As a road safety measure, many countries around the world have promoted the use of adult and child helmets. Australia was one of the first countries to make helmets legally mandatory for cyclists, beginning in 1992.
Curnow et al. carefully studied the mechanisms by which brain injuries occurred in 16 trials, analyzing whether they were due to skull fracture or angular acceleration (rotation of brain tissue and sliding along the inner side of the skull). He said there is significant scientific evidence that angular acceleration is the primary cause of brain injury, but most helmets are designed to resist linear acceleration. In linear acceleration, external forces cause the skull to accelerate rapidly and impact the nearest brain tissue. According to the above theory, to protect brain tissue, helmets should be able to absorb part of the impact energy and reduce the deceleration rate. The current standard helmet design and testing still follow the implausible theory that linear acceleration is the main cause of brain damage, but ignore the angular rotation.
Soft helmets fit snugly against the skull surface of the impacted head, causing the head to rotate and producing strong angular acceleration. Helmet designers did not consider reducing angular acceleration, which is the primary cause of brain injury. But road safety experts disagree with these claims and insist that helmets are reducing the incidence of bicycle-related cranial injuries.
Clinton, of the Royal Society for the Prevention of Accidents, said a recent review published by the UK Department for Transport, which analyzed all available research, concluded that helmets help protect cyclists, especially children. In no sense are helmets the most important safety measure for cyclists, he said, but they are effective.