Alpinestars Bionic Jacket Underlayer

The Alpinestars Bionic Jacket Underlayer is built to sit beneath a riding jacket and add CE Level 1 certified protection at the shoulders, elbows and back, useful for riders whose jacket lacks built-in armor or who want a portable protective layer that moves between jackets. At 620 g in a size medium, the perforated mesh construction stays breathable rather than trapping heat, and adjustable elastic straps hold the whole underlayer in position without needing a tight, restrictive fit. The armor sits at the zones most likely to take an impact in a fall, while the torso stays unencumbered for a natural range of motion at the bars, whatever the riding position.

The mesh fabric moves well with the body, making it practical for long rides where flexibility and airflow matter as much as protection, and the underlayer works equally well worn under a jacket without built-in armor or as an added layer beneath a favourite jacket that already has some protection. The armor is removable, so the mesh shell can be washed separately, and the adjustable straps accommodate a range of body types without needing an exact size match. On warmer rides the ventilation stands out, since the perforated mesh lets air pass through rather than sitting as a solid, heat-trapping layer against the skin, which matters most in stop-and-go traffic during summer.

This underlayer suits riders who want flexible, low-bulk armor that slides under a mesh jacket in summer or forms part of a year-round layering system. The back protector meets Level 1 only, so riders wanting a higher-rated back pad will need to upgrade separately. The mesh can snag on rough surfaces, and the whole piece is not waterproof, so it needs a jacket or outer shell to keep it dry in the rain. Sizing runs a little large for some builds, so checking fit before relying on it for a long tour is worthwhile, particularly for riders with a slimmer frame who want the straps to sit genuinely snug against the body.