How you ride mountain bikes will affect which helmet you need. Full face helmets offer increased protection on the back and chin for downhill riding but they have reduced ventilation and are too bulky for most uphill riders. A few other helmet tips to keep in mind: - Look for downhill certification for full face helmets. - Check your helmet for fit with glasses or goggles. - Look up and see if your visor obstructs your vision. Ready to ride? | FortNine