Buying guide 2026
Start with the fit, then match the rider and the riding style. That is the cleanest way to land on the right S1 helmet without overthinking it.
Step one: get the shell right
Measure the circumference where a hat sits: across the middle of the forehead, above the ears, and around the back of the head. Use a flexible tape measure, or a piece of string measured against a ruler. The Lifer system uses three shell sizes, then sizing liners to refine the fit inside that shell.
For head measurements of 18.5–20.5 inches. This is the smaller Lifer shell.
View Mini Lifer →For head measurements of 20.5–23.5 inches. This includes the standard Lifer family shape.
View S1 Lifer →For head measurements of 23.5–25.5 inches. This is the larger Lifer shell.
View Mega Lifer →Step two: choose the model
The shell measurement gets you to the right family; it does not replace the product-page details. Compare the helmet’s shape, coverage, intended use, and certification information before adding it to the cart.
The standard Lifer profile for riders looking for the core S1 fit. Check the product page for the exact colour, size availability, and standards.
Alternative Lifer silhouettes for riders who prefer a different look. Start with the same head measurement, then compare the specific product page.
More specialised coverage options. Use the product description to confirm the riding application and features before purchase.
Choose from the bike and e-bike range only after checking the individual model’s stated certification and intended use.
Step three: check the final fit
A well-fitted helmet sits level on the head and covers the forehead. It should feel snug without causing pain, and should not rock front-to-back or side-to-side. Adjust the strap so it is secure and use the sizing liners to remove movement. If you are on a shell-size boundary or are unsure after measuring, contact S1 support before ordering.
© S1 Helmets Australia. All rights reserved.
Operated by Trinity Distribution
