Can I pass down a helmet to a younger sibling?

A helmet can be passed down only if it has never been crashed in, is less than 3-5 years old, has been stored properly (cool, dry place, out of sunlight), and still fits the younger child properly. Inspect carefully for any cracks, dents, frayed straps, or degraded foam. If there is any doubt about the helmet's history or condition, replace it. The cost of a new helmet is minimal compared to the risk of a compromised one.