The AI Biker

BIKE AND KIT

Helmet fit and replacement

Fit, inspect and replace a cycling helmet using its own instructions and crash history.

Reviewed · General UK planning guidance · Check current operator and manufacturer information

Fit it correctly

Begin with the correct size and head shape.

  • Position the shell level rather than tipped back.
  • Set retention and straps so the helmet is secure without painful pressure.
  • Recheck with eyewear, hair and cold-weather layers used on the ride.

Before every ride

Look beyond surface dirt.

  • Inspect shell, liner, straps, buckles and adjustment mechanism.
  • Do not ride with loose internal parts or a compromised fastening.
  • Avoid attaching cameras or lights unless the helmet maker approves the method.

Replacement decisions

Follow the specific maker’s service-life guidance.

  • Replace after a significant impact even when damage is not visible if instructed.
  • Replace when fit, straps, buckle, liner or shell are degraded.
  • Do not buy a used helmet with an unknown history.

Useful official guidance

Rules, conditions and services change. Use these sources and the relevant venue’s current information before relying on a plan.

British Cycling helmet guidance

Spot something that needs updating? Tell us about a correction.

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