Four in 10 bikers are riding while wearing helmets that need to be replaced, according to a report from insurance broker Carole Nash.

Some 41 per cent of the 1,000 active riders questioned said their helmet was more than five years old, but experts say that five years is the point at which they should be replaced. More than six in 10 riders (62pc) said they wouldn't replace their lid unless they were involved in an accident. A further 22pc said they wouldn't even replace it then if it still 'looked fine'.

And 63pc said they would carry on using their potentially life-saving helmet even after dropping it, even though it could have sustained internal damage that couldn't be seen.

Pete Horton, who has worked as an online product supervisor at Sportsbikeshop.co.uk for over 10 years, comes into contact with thousands of bikers each year and emphasises the importance of heeding this guidance.

"As the single most important piece of safety equipment a biker wears, it's obviously vital a helmet's integrity isn't compromised in any way to ensure it can provide as much protection as possible," he said.

"Due to the inevitable degradation of the materials used in their construction, we recommend that helmets be replaced after five years of use."

Rebecca Donohue, head of marketing at Carole Nash, said: "While it's encouraging to see that bikers are making an initial investment in their lids, we urge them to not see this as a one-time expense.

"While the costs of a replacement may feel eye watering, why run the risk of the worst happening? With premium manufacturers like Arai offering free helmet checks to their customers, we would even recommend bikers who have just dropped their helmets to get them checked out.

"After all, it's better to be safe than sorry."

For more information visit www.carolenash.com/insidebikes/news-and-reviews/1614-motorbike-helmet-safety-how-safe-is-yours