If you thought that anti-angle grinder locks were the latest tech in bike security, think again. This one – from a French start-up calling itself CactUs – is said to release an “ultra-nauseating gas” if it’s cut in order to deter thieves.

Now, before you think that road.cc is having you on with a slightly early April Fools’ Day joke – this is a genuine invention from France that’s now available for pre-order.

In short, the story is that an engineering student in Lyon, Aïko Leroux, has just launched CactUs Lock, an anti-theft device that emits a foul smell when attacked by a thief. The pre-order phase has begun and it’s hoped that an initial run of 100 units will be available by summer.

CactUs bike lock
CactUs bike lock (Image Credit: CactUs)

Okay, so what exactly do you get here? CactUs is a D-lock/U-lock that is 30cm long and 13cm wide. It is said to be made from a high-strength alloy with an anti-grinder coating and weighs less than 2kg. 

The unique feature is that the lock contains a pressurised gas and emits “a corpse-like smell when cut”.

No footage exists online yet of the lock emitting its odour as far as we can see, but from the images we can see that the lock is clearly labelled to say what it’s capable of, the idea being to discourage any thief from getting involved in the first place. But if they go ahead, the “ultra-nauseating” gas will be released and, CactUs says, the thief will regret their choice because of the god-awful smell. 

And what exactly is that gas? It’s putrescine, which is partly responsible for the foul odour of putrefying flesh. Sounds delightful! CactUs says there is no risk of injury or harm from putrescine at this concentration and volume. However, it is unpleasant and can cause eye irritation and shortness of breath – which can be alleviated by leaving the area and breathing fresh air.

CactUs says the gas cannot be neutralised. Only time can dissipate it and mitigate its effect, and once activated, the lock cannot be re-filled. It is a single-use system.

Hang on, though. Surely, there’s a risk of this stench leaking into your garage, house, flat, or wherever else you lock your bike? CactUs says not. A cut of at least 1cm into the lock’s metal structure is required to release that gas and that’s not going to happen accidentally, while three valves protect the injection system.

Have we been here before? The idea of deterring bike theft with more than just the lock itself is a road that has been reasonably well-trodden – one example is the Oxford Alarm-D Pro, fitted with a 120db movement-activated alarm to scare off would-be thieves.

US-based Skunklock produces a lock that houses “vomit-inducing” chemicals, exposed when it is cut with an angle grinder. Skunklock insists the chemicals are non-toxic and aren’t legally classed as “weaponised”, but it has now produced a non-chemical version because the brand faced “difficulties in terms of selling the original lock in certain countries.” 

As previously mentioned, the CactUs lock is in its pre-order phase. You need to pay €179.99 (around £150) to be in line to receive one from the initial batch. That’s compared with a standard expected price of €259.99 (around £217).

If you’re interested, head over to www.cactuslock.com.

France is known for its fragrance industry, but this is an unexpected turn. What do you think? Let us know in the comments below.