Lezyne has been equipping pumps with the ABS Flip Chuck since 2011. It provides the most stable connection to a valve of any chuck on the market.

The Flip Chuck has its name because each end of it interfaces with either a Presta valve or a Schrader valve - in both cases threading onto the valve cap threads. To switch from one to the other, it un-threads from the swivel/hose connector, so it can be "flipped" 180 degrees and reattached. The new ABS-1 Pro works similarly.

There's a few important things to remember about both of these chucks.

1. When you attach it to a Presta valve, the valve core needs to be threaded to the valve stem tighter than the chuck is threaded to the valve core, so you'll want to make sure these are installed securely. They don't have to be super tight, but should be snug. Even new tubes will likely need their cores tightened. You can use the tool on top of the ABS-1 Pro chuck to do this (or the crown on newer ABS Flex Hoses), as your fingers likely do not have enough grip. To use the tool on the ABS-1 Pro, the plunger for the Presta valve needs to be completely open, then the tool should be able to reach the flats on the valve core.
2. The Presta side of our chucks does not have anything that mechanically opens the valve. It works on air pressure to open the valve after you pressurize the pump and hose. When the pressure is equalized in the pump, hose, and tire, then any pressure added will open the Presta valve and fill the tire. This also means that when you press the air bleed button, the Presta valve immediately closes and you do not bleed any air from the tire. The ABS button is there to break the seal on the valve and help prevent valve cores backing out.
3. The opposite of #2 is true about the Schrader side of the chuck. There is mechanical engagement when connecting to a Schrader valve, so if you hold down the air bleed button, it will bleed from the tire. It also means that you immediately get a pressure reading on Schrader while you do not on Presta.
4. On higher pressure road tires, or valves that may have sealant residue, we recommend giving the valve a quick press before putting on the chuck, as sometimes the higher pressures and gunk can make the valve stick a bit.
5. Thread on the chuck only far enough until it doesn't leak pressure. This should only be a few turns after engagement, and definitely not very tight. Do not over tighten. The seal needs to just land where the stem and core meet on the Presta valve. Threading the chuck on "until it stops" will possibly jam the valve core or plunger in the body of the chuck.

The Flip Chucks are really robust, and we see them fully functional out in the world after years of daily use. That's why the Flip Chuck was incorporated into the design of the ABS-1 Pro. They are also rebuildable. If you are in the United States, you can contact us or your local Lezyne retailer for replacement O-rings. If you're outside the US, please contact your original place of purchase.

If you have any question or problems with your Lezyne chuck, please submit a request for help from our Support Team.