Tubeless tire setup, sealant top-offs, and leaking valve replacements all have one thing in common: you need to remove the valve core first. Park Tool's VC-1 Valve Core Tool is a dual-ended, CNC-machined tool that handles both Presta and Schrader valve cores, plus Presta valve extenders with 5mm wrench flats. One end fits Schrader cores, the other fits Presta cores, and the hexagonal body gives you enough grip to break loose a core that sealant has glued in place.

The most common use case is tubeless maintenance. Removing the valve core lets you pour sealant directly through the valve stem rather than breaking the tire bead, and it also opens up the airflow path so a floor pump or compressor can seat a stubborn bead. If you're running deep-section carbon wheels with valve extenders, the 5mm wrench flats on the VC-1 let you snug those extenders down or remove them without reaching for a separate wrench. It also works for quickly deflating fat bike or mountain bike tires when you need to drop pressure at the trailhead.

One thing to keep in mind: not all Presta valve cores are removable. Some tubes and tubeless valves have cores that are fixed in place, so the VC-1 won't apply in those situations. If you're buying this specifically for tubeless use, your tubeless valve stems almost certainly have removable cores. The tool is made in the USA and small enough to toss in a saddle bag or jersey pocket alongside a plug kit for roadside sealant top-offs.