Sun and heat are the two things to watch for. Leaving a helmet on a dashboard or in direct sun for long periods will dull and eventually crack leather trim, Hedon.com so a helmet bag or a shaded spot makes a real difference over the life of the helmet.

Most manufacturers recommend replacing a motorcycle helmet every five to seven years even without a crash, since the internal materials that absorb impact degrade slowly with heat, sweat and UV exposure. The shell can look fine while the protective layer underneath has already lost some of its effectiveness.

Once the shell is formed and cured, it moves through finishing: sanding, painting or leather trimming, and fitting the internal padding and retention system. Every stage is checked before the next begins, since a fault caught early is far cheaper to fix than one found at the end.

A helmet workshop in London works on a smaller scale than a mass production line, and that shapes almost everything about how a helmet gets made. Materials are chosen and checked by hand, shells are shaped and finished in small batches, and problems are caught by people who see every stage, not just a sensor on a line.

For helmet care products and guidance, see motorcycle helmet workshop.

A certified helmet carries a label inside the shell showing the standard it meets, along with a homologation number that identifies the specific model tested. This label is worth checking on any helmet, since it confirms the exact helmet in your hands passed the test, not just the range it belongs to.