For many years, motorcycle helmets were made primarily of two types of material: mold injected hard plastic, and fiberglass. However, helmet technology has advanced just like technology in everything else. You can now find helmets made of more exotic materials such as carbon fiber and Kevlar.
But there is nothing wrong with the traditional plastic and fiberglass helmets and each has its advantages. The important thing is to find the best combination of comfort, weight, protection and cost for the type of riding you do.
Plastic helmets are still the ones most commonly found. They use a specially engineered plastic that will hold up well to heavy impact, particularly of the type associated with motorcycle accidents. They are designed to offer a good balance between strength and weight. These helmets have a thick foam padding layer under the plastic that is engineered to crush upon impact and thus absorb some of the force that would otherwise be taken by the head. They are also usually the least expensive helmets to buy.
Fiberglass motorcycle helmets offer an excellent combination of hardness and flexibility and are becoming increasingly popular with all types of bike riders. The outer shells are constructed of laminated fiberglass and designed to absorb as much of the blunt trauma of an impact as possible. They are more likely than plastic to experience shatters and cracks, but this “brittleness” is what gives it a “shock absorber” effect and thus less chance of serious injury. While fiberglass helmets tend to be more expensive that plastic helmets, they are also much more lightweight and comfortable to wear, especially on long or hot rides.
Carbon fiber helmets are relatively new and are primarily used in racing helmets, where the extreme protection, extreme lightweight – and correspondingly high cost – is justified. The carbon fibers are produced by superheating acrylic fiber to greatly increase its stiffness and strength, while still remaining very lightweight. This type of composite can produce the strength of metal in a very lightweight unit. These are the hallmarks of a top quality – and top price – bike helmet.
Kevlar, on the other hand, is produced by taking a polymer, dissolving it in a solvent, and using the resulting extracted fibers to spin threads. By itself, Kevlar does not have the protective strength of carbon fiber. But when combined with carbon fiber to produce a laminate, the result is a material that is three times as strong as Kevlar alone. This is truly the best of both worlds, but also results in a very expensive helmet which is for the most part only justified for professional racers.
Regardless of the material, cost, look, weight, or quality of the helmet you choose, bear in mind that wearing any motorcycle helmet is better than going without one. Find one that is within your budget and fits you comfortably. Consider it an excellent investment that, quite literally, can save your life.