Alpinestars Youth SM3 Radium Off-Road Motorcycle Helmet

The SM3 Youth is shaped for kids and younger riders, for motocross, enduro and trail. It takes the technology from Alpinestars' adult helmets and scales it down, and it carries both DOT and ECE 22.06.

The Radium graphic is Alpinestars' design; ours comes in Matte Gray/Black/Yellow Fluo and Gloss Yellow Fluo/Black/Blue.

Parents will like the sizing. The shell comes in three youth sizes (YS, YM, YL), and YM and YL share the same EPS, so a YM helmet can be refitted to YL as your kid grows by swapping the crown and cheek pads. The YS has its own smaller EPS and adjusts through the cheek pads only; Alpinestars says YS riders are typically 3 to 4 years old. It is light: 1,170 g for the DOT version (1,060 g ECE), and the DOT version adds a composite fiber layer between the shell and the EPS. Ten inlets and seven exhausts keep air moving, the cheek pads have an emergency release, and the strap closes with stainless steel D-rings.

If your kid is between sizes, this is the helmet that grows with them.

What stands out

• DOT and ECE 22.06 certified
• Thermo-injected thermoplastic shell in three youth sizes
• YM and YL share one EPS size and refit through crown and cheek pads
• DOT version adds a composite fiber layer between shell and EPS
• Multi-density liner with a low-friction coating for angled impacts
• 10 inlets, 7 exhausts, visor shaped to feed the vents
• Patented visor release
• Emergency release cheek pads with hydration tube channels