Brake light switch, dual pull

Discussion in 'Electrical' started by HoughMade, Jun 11, 2009.

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  1. HoughMade

    HoughMade Guest

    I have the dual pull brake handle on my bike. I am adding a full lighting system, so there is the issue of building a brake light switch. Here is what I did.

    I got a momentary, normally closed, switch from Radio Shack. this means the switch is spring loaded and unlike most swutches, it is always on until you push the button. When you push the button, it goes off.

    Between where the 2 brake cables come into the handle, there is a space a bit ove 1/2" wide. I drilled a small hole between the cables all the way through the handle. the hole is about 3/32". I then determined what size the switch itself is- that is, the switch has threads on it wear it is normally mounted to a panel with a nut. It is about 5/16", but uses a non-standard thread.

    Having determined that I decided to use use a die to reform the threads to a standard 7mm, which is a but under 5/16". I then drilled out the original 3/32" hole to 1/4" about 2/3rds of its depth and threaded it with the 7mm tap. This allows me to thread the switch into the hole between the cables. Now, I need a plunger that would extend out the hole and contact the moveable part of the handle. I grabbed several different sizes of finishing nails and tried them out for size. The head of the nail goes in the hole, and with the head being larger than 3/32, it cannot fall out. I had to experiement with length, but I eventually got it right.

    The way it works is simplicity itself. When your hand is off the brake handle the flat part of the hinged portion of the handle pushes on the plunger and forced it into the hole. The head of the plunger (nail) pushes on the button of the switch and the light is off. When you squeeze the handle, the hinged portion moves away from the stationary portion of the handle and the plunger is pushed out by the spring action of the switch. When you let go of the switch, the plunger is pushed back in and the light goes off.

    Here are some drawings to explain it. I left off the cables for clarity, but just know that the switch mounts between the 2 brake cables.

    Attached Files:

    Last edited by a moderator: Jun 11, 2009

  2. HoughMade

    HoughMade Guest

    For those who may not be familiar with the brake handle, here it is.

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  3. RdKryton

    RdKryton Active Member

    Nice do it yourself. Very clear information. I didn't know Radio Shack still sold electronic parts anymore. It seems like all they have are cell phones. J/K That is the way Whizzer controls the brake light on the front brake. And the rear too if you have the auto clutch.

  4. fetor56

    fetor56 Guest

    Worthwhile idea & something we all need to concider.
    If regulations tighten-up here & demand a working brake light i'll be doing this cheap/relatively easy mod.
    If your not using half the dual brake system for it's intended purpose u might even be able to use that half to mount the switch in.
  5. HoughMade

    HoughMade Guest

    That would make it real easy...I do love my HF 60 piece tap and die set, though.
  6. SirJakesus

    SirJakesus Guest

    Sweet mod Hough.
    This is essentially how the scooter brake levers with switches on my bikes work. The only problem is they're not dual pull. I have a spare dual pull thats the exact same model as the picture so I may use this eventually. However I may just get lazy and use one of those cable activated switches if it comes to that. I have no tap and die set but thats easily remedied.
  7. Hawaii_Ed

    Hawaii_Ed Member

    Nice! I replaced the clutch lever with a scooter lever that had a switch wired in, would love to modify my dual pull like that.
  8. lordoflightaz

    lordoflightaz Member

  9. machiasmort

    machiasmort Active Member

    nice mod Hough, didn't know R/S sold switches that small!
  10. Hawaii_Ed

    Hawaii_Ed Member

    What are the details on the rest of your lights?
  11. HoughMade

    HoughMade Guest

    Here are the the rear turn signals and brake/tail light- all red LEDs. The front turn signals are similar, but amber LEDs. All hand built.

    Right now I just have a 5 watt 12 volt headlight. I power it all with a 7 ah SLA battery. I am making leather case saddlebags. The battery will go in one, the other for stuff.

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