Park Tool VC-1 Valve Core Tool

A valve core tool should be in every toolbox. It’s essential for tubeless installations, but it’s also useful when you run tubes. Sometimes the removable valve cores of tubes aren’t screwed in tightly at the factory, and they slowly leak air. Use the valve core tool to check your valves before you install the tube. That way, you know that if the tire is leaking air, it’s really a puncture, and not just a loose valve.

You can also unscrew the valve core and put a little sealant inside the tube. The sealant will close small holes just like it does in a tubeless tire, but you avoid having to deal with tubeless tire installation.