Bicycle Awareness Siren




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Bicycles in large cities must compete with drivers for space of the road. Distracted drivers can lead to bikes being cut off, doored or worse.

The Bicycle Awareness Siren is the first step to avoiding these accidents. This devices features 2 loud sirens and a strobe light that is used to get a driver's attention.

For a little under 50 bucks you can have the safest bike in downtown!

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Step 1: Supplies

For this device you will need the following:

1 6 Tone Siren
1 Painfully Loud Mini Siren
1 Mini Strobe (Green)
1 12 v AA battery holder
2 switches
2 Rope Hooks
3 Bolts with lock nuts
Velcro Straps
Plastic Container to hold everything
Plastic Container to hold siren trigger

Step 2: Mount the Strobe

First on the front of your holding container mount the strobe light. I drilled 3 holes and pushed in on, using the included nuts to screw it down.

Step 3: Mount Both Sirens

Next mount both sirens to the sides of the box. One siren needed a bolt, the other had some sticky velcro. Be sure to drill holes to thread the wires through.

Step 4: Mount the Rope Hooks

Measure your bike and position the rope hooks so they drape over the handle bars. I used 2 screws to mount them on there.

Step 5: Mounting the Switches

I put the larger switch on the main box to control the strobe. The smaller switch went inside the smaller container to control the siren.

Step 6: Wire It Up

I wired the strobe to the battery and then wired both sirens to the battery through the switch. I used a long piece of wire to go from the sirens to the smaller switch so i can mount the switch wherever i need it.

Step 7: Add Velcro

Use a Dremel to make two slots and fit velcro into both containers. Then run the velcro through each to attach it to the bicycle.

Step 8: Try It Out

Check out the video for the result:

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    18 Discussions


    9 years ago on Introduction

    According to U.S. Laws, you are allowed to have any sound making device, except if it makes a whistling or siren. I don't think there are any restrictions on lights in the U.S.. I think that at night, they have to be visible from a certain distance. On a side note, you can't have red reflectors in the front, or white reflectors in the back.

    4 replies

    Reply 9 years ago on Introduction

    In the US, you are allowed White or yellow. Red is first responders such as fire and ambulance. Blue is police(blue strobe = impersonating police, big no-no). Green is sometimes used by security guards(id avoid it, but not really illegal). Red strobes on a bike should be rear facing.

    Actually, colors depend on locale. I live in the CT, around here, firefighters run blue lights when responding, and EMS responders can run green (Personal vehicles). White helmets (officers) *can* run red. Police have the red/white/blue light bars, fire apparatus runs red and white (some have yellow, too...), as do Ambulances.

    FYI, purple lights are used in funerals.


    Reply 9 years ago on Introduction

    also, I'd replace the siren with an electric car horn or similar. People are more accustomed to hearing a car horn, a car alarm siren is not as ear catching IMO.


    8 years ago on Introduction

    that is the most ugly and useless thing in the world why mate that when you could just get a bell for $5 and then cars and people would know to get out of your way


    9 years ago on Introduction

    There are certain conventional warning sounds-- various car- & truck-horn sounds, bicycle bells, and trolley bells-- which "mean" that a hazardous situation is approaching involving another vehicle. The various sirens that ambulances and fire & police vehicles use have conventional meanings that add the authority of law and all-circumstance right-of-way. But a car-alarm just adds to the cacaphony and noist pollution of city life, and besides, it usually just means that a car with an alarm has been jostled or is being towed, and doesn't "mean" that drivers have any obligation or reason to pay attention unless they're curious. This sound could well turn out to be ineffectual in avoiding accidents for this reason. Even portable air horns can be vague with respect to their "meanings," since they're often used as generic noisemakers, and relying on one once landed me on the hood of an Audi driven by a fery confused woman. ~ For all the potential inneffectuality, a car-alarm sound used like this contributes unnecessarily to noise pollution. The video suggests that the intended use is to ride along with the thing blaring near continually when in congested areas-- if this isn't illegal now, it will likely become illegal soon, just as drivers of cars would find themselves getting ticketed if they drove along blaring their horns for the duration of their passages through congested traffic. As presented, this project doesn't justify its intrusion into the already near-intolerable urban soundscape. ~ Even a car horn might confuse drivers who'd intuitively be looking for a large, wide vehicle as the source of the sound. Perhaps the best approach would be to record a bicycle bell, amplify the snot out of it, and use that as your warning sound-- a sound that means "bicycle approaching." ~ As for lights in the city, I've had great luck with a Cateye LD-130 in white in the front. It has 3 LEDs that blink alternately, and looks like a vibrating light from a distance. I may well get another and mount them side-by-side on the handlebars, but about 6" apart. A single blinking light can appear like a light that's appearing and going out of sight, like many other city lights in traffic, but lights that blink alternatiely provide an unconscious visual reference of constancy of visibility and motion as they blink "against" one another. Cateye also makes a 5-LED version, the LD-150, in white, and the smaller one is only about $12 at Amazon, but an intrepid DIYer could make one for himself. Another good light is the red SpokeLit, which blinks and coordinates nicely with a blinking taillight, as both blink at the same rate while one rotates on the wheel, with the effect of close-together, far-apart, close-together, far apart and so on. Very eye-catching. ~ With this combination I've found that I'm seen in situations I approach with trepidation, like left-turning cars aimed in front of me in heavy traffic. ~ The above is a phenomenological approach to the problem of being noticed. Certain sounds and sights tend to intuitively signal "bicycle approaching," and using signals that signify something else can confuse a driver, who might look for a car to avoid, and end up distracted from attending to the bike that's sending the warning. Working within conventional signals, there are ways to maximize the impact while sending the appropriate message.

    after looking at it some more. what i got out of this instructable for my personal use was the saving of any small plastic containers. i am always trying to think of a use for something before i toss it, but i have to toss stuff, since my apartment is already too overcrowded. i think i have some small plastic containers that were from waterproof ipod holders and other small swimming devices like earplugs and such. i will remember to save them in my junk box for bicycle switch use. some people use the constant sounding sirens and bells on the bike path that runs along the hudson river in nyc, , very irritating/. Out in traffic , you need something that will be heard inside the closed windows of the bus /dump truck/ car that is about to right hook you and run over you. ding ding bellsand circus horns don't cut it. The guys in the nyc puetro rico or rican bike club all have these cylinders with a plunger that sounds like a truck horn. They bing and chrome them up, but one hand has to come off the handlebars .

    2 replies

    Reply 9 years ago on Introduction

    A friend of mine duct taped one of those air horns you are talking about to his fork leg, so he just had to move a foot forwards to blow it in traffic.

    Alternatively you can get an air horn with an external air bottle (search for "Air Zound") which mounts on the handlebar so you can use it with just a thumb.

    Re: legality, I think you are only allowed to have yellow flashing lights for visibility on civilian vehicles in the UK- green is for medical personnel, blue is for emergency services and AFAIK red is for the military, but you can have yellow strobes if you want (as long as they aren't mistaken for turn signals). You might want to check for similar local laws re: sirens as well.

    strobe may be the only think that may be a violation. it all depends on state and munciplaity, or country. i use an air zound that can be bought for around $20 on sale, i have three of four of them mounted on my bikes. They work great , probably louder than this rig, and you can change the stock air containor with a 2 liter bottle, wrapped in duct tape for additional pumping power, which = louder. the tubes need to ne checked every season, but i had a bike i had in storage for a couple of years, it had an air zound mounted, figured it would be dead /flat like the tires. Nope the air zound fired off at full force, it held the 100psi for over 2 years , maybe 4 years, these loud bike noise makers do save your life. however if you drove your bike with the siren going off as the video suggests, That would just piss people off. even with the air zound , only use it when you need it, i am sure the video was done to display the instrutable, not how to use it

    So as an intern, have you had any good pranks pulled on you? If not, please direct me to your coworkers so that I may give them some ...guidance...


    9 years ago on Introduction

    At one point, I had a buzzer, button and battery sewn on the sleeve of my winter coat. The idea was that when I was snowboarding, I could use it as a horn if someone cut me off or what-have-you. The only problem was that it would go off whenever I put my arm by my side! unfortunately, it broke before I could take it on the slopes. Nice instructable. -Noahh