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Add a brake light switch to a bicycle brake lever

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Picture of Add a brake light switch to a bicycle brake lever
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I found a simple way to add a brake light switch to a bicycle brake lever. Specifically, this is for a mountain bike lever that pulls a cable for the brakes although it's possible it could work on other levers. I would not try this on super lightweight brake levers as the metal might not be thick enough to tap threads into and it might weaken the lever excessively.  The switches I used can be found at radio shack and are mini momentary pushbutton switches that are normally closed (N.C.). The tools you will need are: allen and/or box wrenches/sockets, duct tape, half round metal file, pencil, tape measure, center punch, drill and bits, 7mm fine tap and tap holder, wire, solder, soldering pencil, heat shrink tubing, heat gun and electrical tape.
 
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Step 1: Prepping the brake lever

Picture of Prepping the brake lever
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The first thing you will need to do is remove the reach adjustment screw from the body as shown in the first three pictures. This can be done using a small allen wrench. Next you need to remove the lever (silver part) from the body (black part) if possible. This is usually accomplished by removing a pivot screw and nut or a pivot pin and clip. Pay careful attention to how it goes back together and set the lever and small parts aside. Next you want to wrap the body as shown in the picture with a layer of duct tape to protect the finish when you clamp it in the vise.
Progamer7724 months ago
Nice Job. I followed these steps to the letter, on both my front and rear mountain bike brake levels for my brake light and wired the two switches together. So no matter which brake level is pulled, it turns on the brake light. Thank you.
uzzytech9 months ago
when i press the brake lever i want the leds/light to go on and when i leave it they go off
anyone know how or know a source where i can find a project like that or similar?

and by the way Great project!
mefromliny1 year ago
What a great idea and instructable! I volunteer as a fireman and EMT, and I am paranoid about my eight year old riding her bike, even when I'm riding with her. I have the motion-activated rear blinking lights, but this will be something I add on to her bike very soon. I think that I will try doing it with a magnetic reed switch. It should be easier to assemble and probably won't require drilling. Thanks again for posting it! Ken
esemce2 years ago
Next stage of the hack - use the brake cable as the positive conductor and the frame as the ground. so you don't need to run electrical wires.
abikerider (author)  esemce2 years ago
It would be next to impossible to insulate the brake cable from the frame ground.
acewingman2 years ago
Great idea.... Good work.

For the rest of you...For crying out loud, it's a freaking switch. Hook it up between a battery and a light/led and guess what happens next.
abikerider (author)  acewingman2 years ago
You're right, it would be simple if that's all I did. What I actually did to the bike was first install a Blitzen alternator. Then I modified and mounted an LED headlight. Then I made a licence plate/taillight holder and mounted the LED tailight/brakelight to it. Then I installed the brake light switches. Then I mounted a horn and horn switch. Then I built a rectifier/regulator circuit with a bank of supercapacitors and mounted it in a box and attached it to the bike. Then I wired everything up, wrapped electrical tape around the wire bundles and tie wrapped it all to the frame. I'm an electrician by trade but this was something I have never done before. It took a while. I can probably make a series of instructables out of it.
well, from one of your caps or if you have a batteries in your system, you can take a positive (+) to one leg of the brake switch. The switch is not polar, just like a 120 v light switch. Run a wire from the other leg (which is like a switch leg if you are wiring lights in a house), to the positive (+) on the led light. Then from the negative (-) on the led to the negative (-) on the battery or to the frame (if you made it ground).
marple2002 years ago
Looks good.
You might want to show/explain how the thing works on the inside, with the (I assume) normal closed) operation.
The brake lever keeps the button pushed in which breaks the circuit. When the brake is pulled, the button is released, completing the circuit.
I think I'll do this for my motorized bike project.
abikerider (author) 2 years ago
@dangthelad and thrawn1
I completed the brake light wiring on a motorized bike that I made for a friend but didn't document the install with photos. In reality, it's the whole wiring system including headlight, alternator, regulator with supercapacitors, and horn.I am installing it on my bike as well so I plan on documenting it with another instructable. I think I could have a whole series of instructables for this bike! The next instructable will probably be the installation of the 4 stroke Blitzen alternator for the Honda GXH50 and Huasheng 142F engines on the bike.
noahw2 years ago
This looks like a great project abikerider. Good work! You've got me curious about what the rest of the bike brake light system consists of. Any chance you're gonna post the whole thing when it's done?
I would agree with this. I am curious about the entire completed project. It would nice to see how everything works together.
thrawn12 years ago
Nice instructable, well set out with clear photos and good flow. Good to see you are using decent engineering techniques with attention to detail. While functional, a large number out there are using 'duct tape' type methods.
abikerider (author)  thrawn12 years ago
Thanks, this is my first instructable. I really tried to make it a step by step instruction. I try to do quality work.
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