A word about the name. Yes, it looks like German. No, I'm pretty sure it isn't German. While I was designing it, I came up with the name, and realized it'd be a fun tip of the hat to some of the very talented German designers I've come across on Thingiverse, such as CBiker, Modellaner and several others. CBiker was one of the first I came across with a ton of brilliant designs when I started here, and it was Modellaner's work on the spoke tension meter that led to many awesome discussions.

Update: I've posted a complete redesign that does the same thing but is a quick release design so installation and removal are both far easier.

While working on bikes, it's often necessary to deflate a tire to change a worn out tire, to inspect the inside, to replace sealant... several reasons. With a tire having a Schraeder (or car-style) valve, it's easy to grab a small screwdriver or hex wrench and hold the valve open, allowing the air to escape. But - what if you could be doing something else instead of waiting for the tire to deflate? I've already figured out how to turn a generic Presta valve cap into a deflator and use them often (I'll document that simple process and share it) but occasionally get to work on bikes with Schrader valves, and the same trick doesn't work.

Enter this handy little tool. It's a simple thread-on design and has an integrated pin which will hold the valve open for you, while vents allow the air to escape. Need a flat tire? Take off the valve cap, screw this on, and you can continue doing other things while the tire deflates itself.

Similar designs

• Tyre Deflator
• Leaky Valve Cap

Note: Yes, this could be used for nefarious purposes. Just don't.