Fastener

The closure of a motorcycle helmet determines how the helmet stays on your head. Below are the two most common closure systems, with their pros and cons:

• Double D closure: classic system with two metal D-rings. The chin strap threads through both rings and tightens by feeding back through one. Extremely reliable, resists high pull force and is the only permitted closure for competition or track helmets.
• Quick release / micrometric closure: ratchet or buckle mechanism for fast, easy fastening even with gloves. Convenient for daily riding or frequent stops. However, in some (heavy) impact scenarios it offers slightly less security than double D and is therefore not permitted in many competitions.