Everything You Need to Know About Bike Helmets

By Dorothy Yeung

June, 2023




When you ride a bike, wearing a helmet is very important because it can protect you in many ways. For example, it can slow down the impact on your head when you fall, prevent a direct hit on the skull and more. If you don’t wear a helmet, you are at a much higher risk of getting severe head trauma, going into a coma or even dying. Therefore, choosing the right helmet is so important when you bike.


Make sure you get a properly fit helmet in order to get the best protection. There are different types of bike helmets available:

  • Recreational bike helmets (for casual riding).
  • Road bike helmets (designed to be lightweight, well ventilated and aerodynamic).
  • Mountain bike helmets (well-ventilated and offer extended rear head coverage).

How to find a fitted and comfortable bike helmet:

Find your head circumference:

Take a flexible tape measure and wrap it around the widest portion of your head, about one inch above your eyebrows


Bike helmet sizing parameters:

  • Extra small: below 20" (51cm).
  • Small: 20"–21.75" (51cm–55cm).
  • Medium: 21.75"–23.25" (55cm–59cm).
  • Large: 23.25"–24.75" (59cm–63cm).
  • Extra large: above 24.75" (63cm).
  • One size fits all: has a highly adjustable fit system.

How to properly adjust a bike helmet:

  • Adjust the tightness: Turn the adjustment wheel until you get a fit.
  • Buckle and tighten the chin strap: the straps should form a V and rest under each ear.
  • Check the fit: With the chin strap buckled, open your mouth wide and the helmet should press against the top of your head. Repeat the actions if it doesn’t fit.

When to replace a helmet:

It is important to replace your helmet if it has been involved in any type of accident, even if it looks undamaged.



Reference from www.rei.com/learn/expert-advice/bicycle-helmet.html