SkunkLock: The bicycle lock designed to make thieves vomit

A bicycle lock designed to cause would-be thieves to immediately vomit has been developed by two entrepreneurs fed up with seeing their bikes stolen.

The U-shaped SkunkLock – said by US inventors Daniel Idzkowski and Yves Perrenoud to be the first "lock that fights back" – contains an inner capsule of pepper spray-style chemicals that "slam" into the thief's face should they try to cut or break through the device.

"After my friends and I had our bikes stolen over and over we decided to revisit how a lock could deter a thief and start a revolution in the process," Idzkowski says.

"Lock manufacturers won't tell you the fact that any 'U' lock can be compromised with the right tools. The truth is, any lock can be cut in a minute or less ... some electronic locks that have fancy technology like GPS tracking and are app enabled can even be zapped into submission with an inexpensive taser.

"We all know that gut-wrenching feeling of coming back and your bike's gone. That won't happen with the Skunklock."

Launching their $99 (£81, €91) carbon steel lock on crowdfunding website IndieGoGo, Idzkowski said a hollow chamber in each lock contains a "pressurised noxious chemical deterrent that slams the would-be thief".

The irritant, which also sticks to skin and clothing, is said by the lock's inventors to have been tested on themselves and volunteers at various distances between two feet (61cm) and 20ft.

"At two feet it was pretty bad," Idzkowski told the Guardian. "It was absolutely vomit-inducing in 99% of people. At five feet it's very noticeable and the initial reaction is to move away from it. At 10ft it's definitely detectable and very unpleasant."

When asked why the thief couldn't just return later after the chemical has been emitted, he said: "You're basically just puking on yourself the entire time. They could change all their clothes, shower, if the bike is still there come out and cut the remaining 75% of the lock. You can't prevent a theft 100%, so that's why we call it a deterrent lock, not a solution. All you have to do is be better than the bike across the street."

The locks are said to have passed legal and compliance tests in the US, with variations designed to comply with different rules in the EU.

This includes a device containing capsaicin, a chemical found in chilli peppers which is used in pepper sprays. The first locks are expected to ship in June 2017.

Nearly 400,000 bicycles were stolen in England and Wales between April 2013 and March 2014, with London the most targeted city.