Alpinestars 2026 SM3 Helmet - Radium

• Product Details

  Engineered for MX, Enduro, and off-road riding, the SM3 Helmet integrates advanced technologies and innovations designed to enhance ease of use, comfort, and impact protection.

  • Key Features:
  • Advanced Shell Construction: This helmet features a thermo-injected shell incorporating a special polymer blend enhanced by varying degrees of thickness that is engineered to deliver the optimal combination of impact protection and lightweight.
  • The SM3 medium weighs 1430 grams (ECE) and 1460 grams (DOT).
  • Ventilation: Maximized ventilation and high levels of heat transfer exchange thanks to 10 inlets and seven exhaust ports.
  • Rotational Acceleration Force Protection: Alpinestars patented low-friction coating is applied to the inner part of the main EPS liner to reduce the rotational acceleration forces that can result from certain oblique impacts; this layer essentially acts as a slip plane to mimic the brain's own low-friction cerebrospinal fluid, which is the body's natural defense against oblique impacts.
  • Visor Release: Patented visor release system ensures the visor is released with the correct pre-determined amount of force, effectively reducing the forces on the rider’s neck during an impact.
  • Construction:
  • The inner and outer surfaces are engineered to minimize the effects of oblique impacts.
  • Five EPS inner parts with four densities to effectively manage volume and impact performance.
  • Hydration tube channels are integrated into the helmet's cheek pads for convenience and performance.
  • Comfort liner is constructed using recycled materials for a lower carbon footprint.
  • The fit can be tailored to the rider's head thanks to the helmet's crown and cheek pads, which are available as genuine spare parts in different thicknesses.
  • Protection:
  • Alpinestars has introduced a new in-house standard for the SM3 helmet to test the helmet's chin to conditions heavier than the homologation standard, and in order to pass the Alpinestars' new standards, the shell thickness and the structure of the helmet design itself have both been optimized on the chin area for superior impact performance.
  • The inner and outer surfaces are engineered to minimize the effects of oblique impacts.
  • Equipped with an Emergency Release System and removable cheek pads to permit the safe and easy removal of the cheek pads while the helmet is still on, while the 3D contoured foam ensures rider comfort.
  • Soft textile chin strap is 25 mm for optimal safety and rider comfort.
  • Stainless steel D-rings ensure a tight and secure fit.
  • The SM3 helmet conforms to both DOT certification and ECE 2206 homologation for use worldwide.

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• Sizing Info

• # Part Numbers

  Product Variant	Manufacturer Part #
  Black/Flo Red/White / Large	8300826-1553-XL
  Black/Flo Red/White / Medium	8300826-1553-L
  Black/Flo Red/White / Small	8300826-1553-M
  Black/Flo Red/White / X-Large	8300826-1553-2XL
  Black/Flo Red/White / X-Small	8300826-1553-XS
  Black/Flo Red/White / XX-Large	8300826-9510-XS
  Black/White/Grey / Large	8300826-1546-L
  Black/White/Grey / Medium	8300826-1546-M
  Black/White/Grey / Small	8300826-1546-S
  Black/White/Grey / X-Large	8300826-1546-XL
  Black/White/Grey / X-Small	8300826-1546-XS
  Black/White/Grey / XX-Large	8300826-1546-2XL
  Matte Grey/Black/Flo Yellow / Large	8300826-9510-L
  Matte Grey/Black/Flo Yellow / Medium	8300826-9510-M
  Matte Grey/Black/Flo Yellow / Small	8300826-9510-S
  Matte Grey/Black/Flo Yellow / X-Large	8300826-9510-XL
  Matte Grey/Black/Flo Yellow / X-Small	8300826-9510-XS
  Matte Grey/Black/Flo Yellow / XX-Large	8300826-9510-2XL

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