Topic: Rear Brake Stoplight Switch

[Ellz10]

Bike is a 1977 Honda CB750 K. Too much to list as far as what's been done, but the for the sake of this question I pose, I'll say I've went ahead and bought the rearset from CognitoMoto, and unfortunately I have to figure out my own custom mounting for the 77-78 (my bike), for this rear brake stoplight switch.

I'm curious is anyone has had any experience with this and what are some solutions to this.

I'm also curious as to the inner workings and how exactly the rear brake stoplight switch operates - how is the spring, or whatever, relaying an electrical signal to the main box indicating the brake has been applied thus lighting up the rear brake light??

[bryanj]

Spring is attached to pedal and pulls down the spindle of the switch when pedal moved down this connects the two wires going to the switch which puts the light on.
Black is power in when key in on position
Yellow/Green is connected to bulb via loom

[Ellz10]

Spring is attached to pedal and pulls down the spindle of the switch when pedal moved down this connects the two wires going to the switch which puts the light on.
Black is power in when key in on position
Yellow/Green is connected to bulb via loom

I thought the bottom of the spring is just attached to that little nub that juts out of the frame right there?

[stocky]

the end of the spring attaches to the brake pedal like bryanj mentioned. pulling down the spring closes the circuit and sends a signal to the brake light. I personally took mine off for a cleaner look on my cafe. I never just use my rear brake without my front brake anyway, so it's fine for me. 

[bryanj]

If the switch body and the spring both connected to the frame how did you think it would work?

[70CB750]

I used hydraulic switches on Red, it's cleaner solution. 

[newday777]

I used hydraulic switches on Red, it's cleaner solution.

But there's no hydraulic on the rear drum brakes this is about.....

[Ellz10]

Thank you to all the replies. For some reason I just could not see it in my mind - how it functioned, that is. Brain fart I suppose. The knowledge is much appreciated.

[bryanj]

Rarely do i dissagree with tt but this time he has it wrong, the switches are on the power in side and the bulb is groubded via the casing

[TwoTired]

Rarely do i dissagree with tt but this time he has it wrong, the switches are on the power in side and the bulb is groubded via the casing

You are correct.

[bryanj]

We all get it wrong sometime, and old boss of mine used to say "him that makes no mistakes does nothing"

[Kelly E]

We all get it wrong sometime, and old boss of mine used to say "him that makes no mistakes does nothing"

That's a good one.

[Stev-o]

For some reason I just could not see it in my mind ...

I used an aftermarket spring on my K3, sorry, I dont recall where I got it.