cross-country bicycle and cyclist
Cross-country bicycle: relatively small, sturdy bicycle designed for performing acrobatics and competing in competitions on rough terrain.
back suspension 
Device that dampens vibrations from the wheels; this increases the bicycle’s stability and its grip on the trail.
clipless pedal 
Pedal with a safety system so that the foot can be attached or detached quickly.
front fork 
Fork whose air/oil or elastomer suspension provides a controlled ride over rough terrain.
goggles 
Eyewear with plastic lenses fitted in a frame with arms; it protects the eyes from flying mud, stones and insects.