Dirt bike helmets are different than street bike helmets because they serve different purposes because of several reasons that include the protection of dust flying over the helmet while Riding in the field, also to keep the sun out of your eyes, ventilation, and lighter weight, because dirt bike helmets aren't ...

Why are off road helmet shaped differently?

Why are off-road helmets shaped differently than motorcycle helmets? ... The small vents ensure adequate ventilation at higher speeds, but at speeds below 30mph, they do not allow enough air into the helmet. The result is fogging on the inside of the visor.

Can you wear off road helmets on road?

Are they good for road travel? Not exactly. Dirt helmets are designed for slower speeds and are built for lots of bumps. They don't do very well under high speeds with all the big protruding parts getting caught in the wind.