Wearing a cap under a bike helmet is not recommended. Helmets are designed to be worn directly on the head without any additional layers, including caps or hats. Here are a few reasons why it is best to avoid wearing a cap under a bike helmet:
Fit and Safety: Helmets are engineered to fit snugly on the head to provide maximum protection in case of an impact. Adding a cap underneath can interfere with the helmet's fit and compromise its effectiveness. It can create an improper fit, reduce stability, and potentially affect the helmet's ability to absorb impact energy.
Impaired Ventilation: Bike helmets are designed with vents to allow proper airflow and heat dissipation, keeping the head cool during rides. Wearing a cap underneath the helmet can impede ventilation, leading to increased perspiration and discomfort.
Increased Friction and Discomfort: Adding a cap under the helmet can create additional friction and pressure points, leading to discomfort and potential chafing or irritation of the scalp. This can make your ride less enjoyable and may cause distractions or discomfort during longer rides.
It's best to wear the helmet directly on your head, ensuring a proper fit and following the manufacturer's instructions. If you feel the need for additional head coverage or sun protection, consider using a helmet with an integrated visor or opting for a separate lightweight, breathable, and moisture-wicking headwear specifically designed for sports activities that can be worn comfortably under a helmet, such as a cycling skull cap or a bandana.