So you want to be loud? You want to make a statement? You want to scare the crap out people? A train horn will do the trick. Do you want to stand out in the process? Than a bike with a train horn attached will defiantly do the trick!

So you may be asking yourself why would you possibly attach a train horn to a bike? Well the first reason is that I currently do not own an automobile, so this is the best that I can do. The second reason is that it just so unexpected and fun to use. Have you ever heard a train horn in the middle of the street and seen that it was coming from a bike? I didn't think so.

To start off, let me explain some things:
1. The reason why there is a portable air tank on the back of my bike is that hooking up an air horn to an air tank is much louder than attaching an air horn with the provided compressor.
2. The horn I used can be heard from over half a mile away. Although this is not as loud as an actual train horn, it does the job.
3. The total cost of the project varies. If you happen to already own all of the materials, it will cost nothing. If you own none of the materials, it could cost over $200 to construct.
4. It takes about 30 minutes to construct.
5. This is an extremely fun way to scare/prank innocent pedestrians, although it should be used respectively. Blowing it near traffic is NOT a good idea!

Step 1: The Bike

The most important part of this instructable is of course the bike that your going to be using. While you could use any bike for this project, a cruser is 100% recommended. The reason why I recommend a cruser is that most of them include luggage racks on the back. This luggage rack is vital because this is where you will place your air tank.

* If you do not have a bike with a luggage rack, you could build one using either wood, metal scraps, or even PVC pipes.
Some nice instructables on building bike luggage racks...
carpespasm's instructable
darlingtom's instructable
graphicsman's instructable

Step 2: Materials Used

Materials Used:
    - A 10-gallon air tank. (Any tank will work)
    - Dual trumpet air horn. (Any large horn will work)
    - 2 bungee cords (Any strap will do)
    - Duct tape
    - Air blow gun attachment for air tank
    - 4 foot long 1/2 inch thick hose (running from the air tank to the horn. Any length of hose will do)

Optional Materials:
    - An old towel (so the air tank doesn't scratch the bike luggage rack)
    - A large hose clamp (for placement of the horn)

Costs:
Air Horn-   Any where from $15 to $200 on Amazon. The one i used is HERE
Air Tank- Any where from $30 to $60. I used some old tank. You can buy them HERE
Bungee Cords/ Straps- Very cheap @ any local hardware store. About $5 each.
Air gun attachment, duct tape, hose, and large hose clamp- Very cheap @ any hardware store.

Step 3: Attaching Materials to the Bike

Now that you have your bike ready and your materials on hand, it is time to construct it all.

Before Attaching the Materials:
1. Fill up the air tank with air. Over half a tank is recommended.
2. Make sure that your portable air tank is attached to a piece of 1/2 inch thick hose. The length of the hose is up to you.

Steps To Attaching The Materials:
1. If you don't want to scratch your luggage rack on your bike, place a towel down.
2. Set your air tank on top of the luggage rack.
3. Take your bungee cord or strap and wrap it around the air tank and the frame of the bike. (Be sure to wrap it around a secure spot on your bike frame)!
4. Take your other bungee cord or strap and wrap it around a different spot on the bike frame and the air tank. (Attaching any other cords/straps for extra support is recommended but optional).
5. Take your hose running from the air tank and strap it on the frame of the bike using (duct tape) until it reaches the handlebars on the bike.
6. Try to place the blow gun attachment at a comfortable position on the handlebar. Strap it down with duct tape.
7. Attach the blow gun attachment at the end of the hose to the hose from the air horn.
8. Position the horn on the handlebar. This is where the hose clamp may come in handy. Luckily this bike has a cup holder to position the horn on so a hose clamp is unnecessary.

Step 4: Test Drive

You are finished! Now that wasn't so hard, was it? To blow the horn, simply make sure that the air tank valve is open and push down the lever on the blow gun attachment.

Now that your amazing project is completed, it is recommended for pranks, scares, showing off, and just having fun. The possibilities are all up to you!

Please comment and favorite if you like it! This is my first instructable so please follow me for cool new ideas. Oh and one last note, if you see the police, i DON'T recommended blowing the horn.