Technology has come a long way in producing materials to suit a wide variety of automotive safety purposes, and motorcycle helmets are just one such application. Today's helmets are designed to be both comfortable and lightweight, while providing enough protection to properly cushion the user's skull against the impact of a collision.
The materials that are chosen to go into any particular model are chosen based on the properties the manufacturer wishes the helmet to exhibit during a crash. The helmet must take the brunt of the impact while dispersing as much kinetic energy as possible before it is transferred to the wearer's skull. Since crashes take place at a huge range of speeds, and impacts tend to occur against a wide variety of foreign materials, it is difficult to rely on a single helmet construction to be able to protect against every situation.
Primary Types of Materials Typically Used
- Mold injected plastic
- Carbon fiber
Plastic Helmets are most Common
The type of plastic used in the outer shell is specifically engineered to meet the demands of standing up to blunt trauma. It is extremely hard, but at the same time not overly dense. If a motorcycle helmet is made to be too heavy, it discourages a rider from regularly using it. This special plastic offers the perfect compromise between strength and weight.
Beneath the exterior shell is usually a thick layer of foam padding. It is the same type of foam that makes up crunch zones in the bodies of modern automobiles. Under normal conditions, it's quite sturdy. However, it is designed to crush on impact, and not to resist the force of the blow. By crushing, some of the impact is absorbed by the foam material instead of being transferred to the wearer's head.
Fiberglass Offers Greater Flexibility
Premium motorcycle helmets are typically built with a bit more flexibility in mind. The outer shells of these are usually laminated fiberglass, and they are made to soak up as much impact as possible. They are much more prone to cracks and shatters than their plaster counterparts, and that slight brittleness is part of what helps give them as much shock absorbing capability as possible.
Fiberglass helmets represent one of the best possible mixes of hardness and flexibility, and are one of the most popular choices among motorcycle enthusiasts. Fiberglass also has the distinct advantage of being extremely lightweight, so these high quality helmets tend to stay comfortable even during long rides.
Racing Helmets Demand Extra Protection
Racing or other high performance helmets are generally made out of more exotic materials. Some examples are woven Kevlar, as well as certain kinds of carbon fiber. To be sure, these make for an exceptionally strong motorcycle helmet, but they aren't practical for everyday riders. The kinds of impacts racing helmets are designed to protect against are much greater than what a typical crash victim would experience. For most people, the considerable extra cost of helmets made from these high end materials just isn't justified.
Above all, it's important to keep in mind that any helmet is always going to do more good than no helmet at all. Investing in one that's comfortable and affordable is an investment in your own personal safety.