DEEMEED Security Helmet Bag Double: theft-proof helmet bag

The coffee stop is planned, the ice cream parlour is already in sight; and up pops the question that follows us on almost every ride: where do we put our helmets and gear? Very few bikes offer enough storage space, and even a top case fills up quickly or is simply too small - at the latest when two helmets plus gloves, neck scarves and kidney belts need to be stowed. So do we lug all that stuff through the old town? Or leave the gear on the bike and hope nobody helps themselves, nothing gets damaged in the cramped car park and the weather plays along?

Because even if it's only rainwater, slipping into a wet helmet after a relaxed break is no fun. That's exactly the question that accompanied us throughout this 1000PS Performance Check: can our helmets stay safe and dry on the bike while we stroll leisurely through town? More on that later.

Tomasz Jasiński recognised this problem too. The owner of DEEMEED from Bielawa in Poland presented a well-engineered answer at the The Newchurch Summit 2026 festival in Neukirchen - according to the manufacturer, the world's first theft-proof helmet bag. It comes in four versions: as a Single for one helmet and as a Double for two helmets, each optionally with a hard-to-miss alarm lock. The alarm remains optional, because only when locking up do you decide with a single move whether the lock makes noise when moved or simply secures mechanically. We tested the top-spec version: the DEEMEED Security Helmet Bag Double + Alarm for 249 euros.

Our picture story uses three real-world scenarios to show how differently a perfectly ordinary ice cream stop can play out.

The DEEMEED Security Helmet Bag Double + Alarm comes with a large, sturdy alarm lock. Two helmets pictured on the packaging identify the Double version. Inside you'll find the rolled-up helmet bag with steel pull cable and hook-and-loop strap, the small orange padlock, the alarm lock with three keys and - pleasingly - a second battery pack with six LR44 button cells in addition to the six already fitted in the lock. The transport pouch made of thick fabric looks like a small roll bag and features two buckles plus a sturdy mounting strap that lets you lash it to the handlebar, the frame or onto panniers.

The DEEMEED Security Helmet Bag protects its contents with an integrated mesh made from a total of 18 metres of steel cable, running between two layers of fabric. DEEMEED calls this construction Steel Web technology and has registered the helmet bag as an EU design, as indicated by the sewn-in label and the instruction leaflet. This protects the design of the bag and not, as a patent would, the technical working principle behind it. Whether DEEMEED really was the first manufacturer in the world to develop this solution cannot be independently verified. We did, however, measure the cable thicknesses ourselves: the steel cables of the protective mesh have a diameter of 3.5 mm including the plastic sheathing, with the steel core measuring 2 mm according to the manufacturer. The pull cable at the bag opening is considerably beefier at 7 mm outer diameter and is said to have a 5 mm steel core.

The outer shell is made of waterproof nylon, while on the inside soft, signal-orange Evolon protects the delicate surfaces of the helmets. According to the material labelling, the textiles used come from France. Development and production of the helmet bags also take place in Europe, according to the manufacturer. DEEMEED also offers custom designs for dealers, clubs and event organisers, which can be produced even in small quantities.

The transport pouch impresses with solid build quality. Its mounting on the bike proved reliable throughout our test rides. At no point were we worried about losing the compactly packed helmet bag on the road. We do see room for improvement in the closure of the transport pouch, though: to take out the helmet bag, you first open the mounting strap and then loosen the drawstring. This is tied with a simple cord whose loose ends, if not knotted properly, can flap around while riding and slap against the bike. A properly tied bow easily prevents this, but a buckle like the one on the mounting strap would have been more practical and more elegant here.

The rolled-up helmet bag slides out of the transport pouch without much effort. A hook-and-loop strap keeps it compact. As soon as it's released, the bag literally leaps open like a tree frog and is ready to use almost instantly. From the outside, the integrated steel cables are clearly noticeable, which is why we expected a rather rough surface on the inside. But the opposite is true: the signal-orange Evolon lining feels pleasantly soft, almost velvety. No steel cables poke into the interior, nor can you feel any annoying seams. Especially for NoPain, who is extremely fussy about his expensive helmets, this was a pleasant surprise. The initial scepticism was gone.

The correct sequence when closing is crucial: once the bag has been carefully filled, the pull cable is first tightened until the bag opening cinches shut. Then the eyelet must be passed completely through the tab at the end of the cable. Only then is the lock shackle pushed through the eyelet. This is the only way the opening is sufficiently secured and can no longer be pulled apart far enough to remove items. Anyone who skips this crucial step has locked the bag, but not truly closed it.

To prevent the bag from disappearing along with its contents, the free end of the steel cable is routed through the front wheel or around the fork, and the second loop is hooked into the same lock. Routing it through the front wheel in particular further increases theft protection. If you park the bike right next to a fixed object such as a metal post, you can also loop the cable around it before the lock snaps shut. According to DEEMEED, easily removable add-ons such as a sissy bar, luggage rack or backrest can also be threaded onto the steel cable and secured at the same time.

The alarm lock features a motion sensor and a hardened steel shackle. According to the packaging, the alarm reaches a sound pressure level of 110 dB(A). Particularly practical: the lock can be used with or without the alarm function. Which mode is active depends solely on which way round the shackle is inserted. The key is a small groove on the steel shackle. If it faces the side of the lock cylinder, the motion sensor is activated and the lock responds to vibrations with an alarm. Turn the shackle 180 degrees and insert it the other way round, and the alarm stays deactivated. The lock then works like an ordinary padlock.

With the alarm lock, the small padlock can stay at home, but nothing changes in the actual locking principle. The eyelet must be pulled completely through the tab at the end of the cable before the lock shackle is pushed through the tab (!). Otherwise the bag opening can still be pulled apart far enough to remove items despite the lock being engaged. DEEMEED demonstrates in a dedicated video how easy it is to switch between the two modes. The construction in detail can be seen in our studio photo gallery.

Unpacking is done in reverse order: remove the lock, open the loops and pull the steel cable fully apart. Then comes the part we had underestimated. Cable, loops and lock go into the empty bag, and folding it up afterwards is a real workout without practice, because the transport pouch is tightly cut - fold the bag wrong and it won't go back in, which is why we warmly recommend the packing video from DEEMEED to everyone. Stick to it and things get much easier: fold the bag sideways, lay it with the hook-and-loop strap facing you, fold it almost in half, roll it up as tightly as possible from top to bottom and immediately secure it with the hook-and-loop strap.

After that, the compact bundle slips back into the transport pouch relatively easily, ideally with the big alarm lock going in first so it doesn't fall out the side later. The effort noticeably dampens the joy at first, but a few practice runs take most of the sting out of it.

The DEEMEED Security Helmet Bag Double + Alarm accompanied us on every weekend tour for around eight weeks. For our photo gallery it was used on the BSA Scrambler 650 from the 1000PS test fleet, which NoPain rode with his daughter Alva as pillion. The BSA has neither a top case nor side panniers, offering exactly the scenario in which the helmet bag is supposed to play to its strengths.

The transport pouch could be mounted on the frame on the right below the seat, where it barely stands out, takes up no additional storage space and adds little bulk even with the alarm lock stowed inside. Depending on the bike, crash bars, handlebars, the area below the headlight, luggage racks, pannier systems or the MOLLE loops of suitable luggage solutions are also possible mounting points. If need be, the compact roll also disappears into a backpack. There, however, the extra 322 grams of the alarm lock are more noticeable than when mounted directly on the bike.

In the centre of Wiener Neustadt we park the BSA by the old city wall. The helmet bag is quickly unrolled and first takes the two full-face helmets before the accessories find room on top. We then cinch the bag opening shut with the steel cable, pass the eyelet through the tab and secure the bag to the front wheel with the alarm lock.

Tip: with the alarm function activated, only remove the key once the bag is hanging upside down from the handlebar. Otherwise the motion sensor may trigger the alarm while you're hanging it up, which you'd be well advised to avoid. Because the warning tone is extremely shrill and loud. We didn't carry out a sound level measurement, but given what our ears told us, the manufacturer's stated 110 dB(A) seems entirely plausible. Either way, the alarm certainly grabs attention.

To protect it from rain, the filled bag then hangs upside down from the handlebar. It's held by a generously sized hook-and-loop strap that easily carries even the weight of two full-face helmets. Next to the tank, the black package barely stands out visually. And with the opening facing downwards, no rainwater can get in directly from above.

During our eight-week test we were also caught by a heavy downpour, which the bag weathered without any problems in this position. The result was pleasing: no water got inside, though cool, damp air did. So the gear isn't sealed airtight, but it is reliably protected from direct rain. The bag doesn't replace a waterproof luggage box, but in our test it did prevent a soaked helmet after the break. We didn't check how watertight it is when the bag is lying on the ground; after all, hanging it up is part of the intended concept of use.

Instead of tucking helmets and the rest of the gear under our arms, we head off hands-free for an ice cream and an espresso, without glancing over at the bike every few minutes. When we return, everything is still there, and shortly afterwards both of us are ready for the evening run through the twisties.

For all our enthusiasm, in fairness we also have to address the limits. For short stops, such as refuelling or a quick shop, packing and unpacking is too much hassle, which is why a classic helmet lock or a permanently mounted helmet security device gets the job done faster there. The DEEMEED plays to its strengths as soon as the bike is left unattended for longer.

It also remains open how long the integrated steel mesh can withstand a targeted attack with a knife. We refrained from a destructive cut test, which is why its actual resistance cannot be conclusively assessed.

The capacity, on the other hand, is clearly defined. The Double holds either two helmets, one helmet plus a jacket, or two light jackets, with size and protectors being the deciding factors. What else fits alongside two helmets depends heavily on their size. According to its own tests, DEEMEED manages to fit two Schuberth full-face helmets in XL, while next to Alva's youth full-face helmet with its smaller outer shell we even had room for considerably more. Adventure and enduro helmets with a large peak, by contrast, usually don't fit two at a time; in that case the only option is to pack one helmet or remove the peaks.

The DEEMEED Security Helmet Bag can do far more than just secure helmets on a bike. After all, the basic principle works completely independently of biking: anything that fits in the bag can be locked away together and attached to a suitable object via the steel cable. This turns the helmet bag into a versatile security solution for leisure, sport and travel. We didn't try out these uses away from the bike, but there's no shortage of practical ideas.

When taking a spontaneous dip in the lake, valuables and clothing stay secured on the shore; at a festival site, gear can be given extra protection overnight. At the campsite, a camera, power bank and other valuables could be attached to a tree or a sturdy structure, while at the beach your backpack, smartphone and car keys disappear into the bag. The DEEMEED would also be interesting for e-biking, for example for bicycle helmets and a removable battery, provided its dimensions fit. When skiing, ski helmets and a backpack could be secured during the hut stop, and even a laptop or tablet could be additionally locked away in the car if needed. The only requirement is a sufficiently sturdy anchor point through which the steel cable can be routed. Of course the bag doesn't replace a safe, but it makes life considerably harder for opportunistic thieves. And that's exactly the point.

What does the DEEMEED Security Helmet Bag cost? In the manufacturer's shop, the DEEMEED Security Helmet Bag costs 139 euros as a Single, 189 euros as a Single with alarm lock, 219 euros as a Double and 249 euros as a Double with alarm lock. The alarm lock is available separately for 45 euros; all prices plus shipping, as of October 2026.

Do two helmets fit in the DEEMEED Security Helmet Bag Double? Yes, with 42 litres the DEEMEED Security Helmet Bag Double holds two full-face helmets, according to the manufacturer even two Schuberth full-face helmets in size XL. Alternatively, one helmet plus a jacket or two light jackets fit inside, depending on size and protectors, but not two helmets plus two jackets. Adventure and enduro helmets with a large peak usually only fit individually or with the peak removed. The Single holds 21 litres for one helmet.

Is the DEEMEED helmet bag waterproof? Hanging upside down from the handlebar, the DEEMEED Security Helmet Bag keeps rain out; during a downpour in our test, no water got in. Cool, damp air does get inside, however, so the helmet bag isn't hermetically sealed. 1000PS did not test it in the rain lying on the ground.

How secure is the DEEMEED Security Helmet Bag against theft? Theft protection on the DEEMEED Security Helmet Bag comes from a mesh of 18 metres of steel cable between two layers of fabric, designed to make cutting it open more difficult. The pull cable at the opening measures 7 mm and is secured to the front wheel with the small lock or the 110 dB(A) alarm lock. 1000PS did not carry out a cut test.

How do you switch on the alarm on the DEEMEED alarm lock? You select the alarm via the orientation of the shackle when inserting it. If the groove on the shackle faces the side of the lock cylinder, the alarm of the DEEMEED alarm lock is active; if it faces the opposite side, it only locks mechanically. To switch, the shackle is removed and rotated 180 degrees.

How much does the DEEMEED Security Helmet Bag Double weigh? The DEEMEED Security Helmet Bag Double weighs 1,186 grams including the transport pouch and small lock. The alarm lock tips the scales at 322 grams with batteries fitted, making 1,508 grams in total. 1000PS weighed both items on a kitchen scale.