Valves & Valve Caps Valves and valve caps play an important role in maintaining tire pressure and performance. Choose between Presta and Schrader valves based on your bike's design. Ensure caps fit securely to prevent dirt and moisture from entering your tires. Replacement valve cores are useful for fixing leaks without replacing the entire valve. At Planet Cyclery, we offer a variety of valve accessories to help you keep your tires in peak condition.