A helmet only helps if it stays put. Look for level fit (not tipped back), snug cradle or dial, and a strap that forms a V under each ear with room for about two fingers under the chin buckle.
Replace after a crash impact, or when foam is cracked, straps fray, or the manufacturer’s useful life guidance says it is time — even if it “looks fine.”
Stub — add sizing charts and brand-agnostic fit photos later.
