Start with the head measurement.
Mini Lifer covers 18.5–20.5 inches, standard Lifer 20.5–23.5 inches, and Mega Lifer 23.5–25.5 inches. Measuring gives you the best starting shell.
About S1 Helmets Australia
S1 is known for helmets and pads that put protection first. The Lifer family uses Fusion Foam construction, multi-impact protection, and a fit system that helps riders get to the right size without guesswork.
The S1 Lifer fit system
The practical difference is not just the label on the box. Mini Lifer, standard Lifer, and Mega Lifer are different shell sizes. Within each shell, the colour-coded sizing liners can be changed to make the helmet feel snug and stable for the rider.
Mini Lifer covers 18.5–20.5 inches, standard Lifer 20.5–23.5 inches, and Mega Lifer 23.5–25.5 inches. Measuring gives you the best starting shell.
Once the shell range is right, sizing liners adjust the internal fit. The goal is a helmet that sits level and does not move independently of the head.
Each product page is where to confirm the available size, model-specific features, certification information, and intended use before buying.
Get the fit right
That sequence helps you choose the right S1 helmet family first and reduces the chance of ordering a shell that does not suit the rider. Use the detailed size guide if you need help with a measurement or liner choice.
