Basic types
Modular or "Flip-up" Helmets
A hybrid between full face and open face helmets for street use is the modular or "flip-up" helmet, also sometimes termed "convertible" or "flip-face". When fully assembled and closed, they resemble full face helmets by bearing a chin bar for absorbing face impacts. Its chin bar may be pivoted upwards (or, in some cases, may be removed) by a special lever to allow access to most of the face, as in an open face helmet. The rider may thus eat or drink without unfastening the chinstrap and removing the helmet.
As of 2008 there have not been significant scientific studies of modular helmets to assess how protective the pivotable or removable chin bars are. Evidence suggests that at least some greater level of protection exists beyond that for an open face helmet. When testing modular helmets for compliance with DOT, Snell, ECE, and other standards, however, only the open face helmet criteria are certified.
Open face or 3/4 Helmets
The open face, or "three-quarters", helmet has a rear which also covers the back of the skull, but lacks the lower chin bar of the full face helmet, and does not necessarily include a face shield. Many offer visors of selectable length which may be used by the rider to reduce sunlight glare. An open face helmet provides the same rear protection as a full face helmet, but little protection to the face, even from non-crash events.
Bugs, dust or even wind to the face and eyes can cause rider discomfort or injury. As a result, it is not uncommon (and in some states, is required by law) for riders to wear wrap-around sunglasses or goggles to supplement eye protection with these helmets. Alternatively, many open face helmets include, or can be fitted with, a face shield extending over the upper portion of the face to protect the eyes.
Half helmet
The half helmet, also referred to as a "shorty", has essentially the same front design as an open face helmet but with a raised rear. The half helmet provides the minimum coverage generally allowed by law in the U.S. As with the open face, it is not uncommon to augment this helmet's eye protection through other means. Unlike open face and full face helmets, half helmets are also prone to shifting and sometimes coming off of the rider's head during an accident. Because of their inferiority compared to other helmet styles, some Motorcycle Safety Foundation courses prohibit the use of half helmets during riding exercises.
Headwear not intended for motorcycling
There are other types of headwear - often called "beanies" or "novelty helmets" (a term which arose since they can not legally be called "motorcycle helmets") - which are not certified and generally only used to provide the illusion of compliance with mandatory helmet laws. Such items are often smaller and lighter than DOT-approved helmets, and are unsuitable for crash protection because they lack the energy-absorbing foam that protects the brain by allowing it to come to a gradual stop during an impact. A "novelty helmet" can protect the scalp against sunburn while riding and - if it stays on during a crash - might protect the scalp against abrasion, but it has no capability to protect the skull or brain from an impact.
Motorcycle Helmet Visibility
Although black helmets are popular among motorcyclists, they offer the least visibility to motorists. A rider wearing a plain white helmet rather than a black one reduces his or her chance of collision by 24% because it is so much more visible — day or night. Nevertheless, black helmets outsell white ones (photo, above) by 20:1. Helmets of other colors vary in the visibility they provide to motorists by where they fall on a scale from black to white.
Helmet Construction
Modern helmets are constructed from plastics. 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 a 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. |