Take on the mountains at your on pace on the Ozone 500 Boys' Exhilarate 20 in Mountain Bike. The Index 18-speed Shimano rear derailleur with twist grip shifter allows you to navigate different types of terrain, and the alloy rims and larger tires help absorb shock for a comfortable ride. The front and rear V-brakes provide complete stopping power, and the 20-inch steel frame resists wear and tear from the elements.