If you can only choose one piece of gear when going out for a ride, it must be a helmet.
Helmets are categorized into in-mold helmets and non-in-mold helmets based on the manufacturing process of the shell and the EPS (Expanded Polystyrene) foam layer.
The EPS foam layer is the core component that absorbs and cushions external impact during an accident. When a collision occurs, the helmet takes the brunt of the impact, helping to absorb most of the force, which is why it's common to see the helmet cracked but the rider's head unharmed.
If you're looking to buy a road bike helmet, it should have:
Aerodynamic Design: Reduces wind resistance.
Good Ventilation: Keeps your head cool. The main goal is to protect your head while also allowing you to maintain speed.
For mountain bike helmets, choose ones with:
Visor: Provides protection from the sun and branches.
More Angular Design: Offers better protection in rugged terrain with many trees.
When selecting a helmet, make sure to choose one from a reputable manufacturer that fits your head size properly to ensure safety. Additionally, if your helmet has been in an accident, do not use it again.