Riprock 20Specialized Riprock 20 The Specialized Riprock 20 is built to give young riders more confidence, more control, and more fun every time they jump on the bike. With proper mountain bike features like hydraulic disc brakes, wide 20 inch tyres, modern kid focused geometry, and simple 1x8 gearing, the Riprock 20 is ready for family rides, bike paths, pump tracks, and beginner trail adventures. Specialized designed the Riprock around comfort and confidence.