Motorcycle Helmet Topics

• motorcycle helmets
• face shields
• foam interiors
• impact speed
• motorcycle safety
• helmet motorcycle
• first impact
• visible damage
• ear protection
• premium price
• deceleration
• available space
• head injury
• kevlar
• carbon fiber
• helmet safety
• stiffness
• intercom
• conveniences

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Motorcycle Helmet, Motorcycle Helmet

The primary goal of a motorcycle helmet is motorcycle safety - to protect the rider's head during impact, thus preventing or reducing head injury or saving the rider's life. Some helmets provide additional conveniences, such as ventilation, face shields, ear protection, intercom etc.

Premium price helmets are sometimes reinforced with kevlar or carbon fiber. They generally have fabric and foam interiors for both comfort and protection. Motorcycle helmets are generally designed to break in a crash (thus expending the energy otherwise destined for the wearer's skull), so they provide little or no protection after their first impact. Note that impacts may, of course, come from things other than crashing, such as dropping a helmet, and may not cause any externally visible damage. For the best protection, helmets should be replaced after any impact, and every three or so years even if no impact is known to have occurred.

The required stiffness depends on the impact speed of the head, which is unknown at the time of manufacture of the helmet. The result is that the manufacturer must choose a likely speed of impact and optimize the helmet for that impact speed. If the helmet is in a real impact that is slower than the one for which it was designed, it will still help but the head will be decelerated a little more violently than was actually necessary given the available space between the inside and outside of the helmet, although that deceleration will still be much less than what is would have been in the absence of the helmet. If the impact is faster than the one the helmet was designed for, the head will completely crush the liner and slow down but not stop in the process. When the crush space of the liner runs out, the head will stop suddenly which is not ideal. However, in the absence of the helmet, the head would have been brought to a sudden stop from a higher speed causing more injury. Still, a helmet with a stiffer foam that stopped the head before the liner crush space ran out would have done a better job. So helmets help most in impacts at the speeds they were designed for, and continue to help but not as much in impacts that are at different speeds. In practice, motorcycle helmet manufacturers choose the impact speed they will design for based on the speed used in standard helmet tests. Most standard helmet tests use speeds between.

Source: Wikipedia > Motorcycle Helmet