Brake..Motor kill switch.

[sissonscott]

Well now that my bike is all done and running great ( Boygofast 67CC motor) , I had the chance this weekend to put some real miles on it. Every thing went great except for a small incident with a large squirrel who wanted to take a very close look at my new toy. I put the brakes on and did not have enough time to pull in the clutch, I was going 20 MPH and stopped just short of him.
I was very disappointed in my stopping distance, it was way too long !! If that had been a small child or a car backing out of a driveway it could be a big problem. I realize that I was fighting the motor to some extent during this emergency stop.

I gave it some thought and I came up with a very simple solution:
I took one of these water resistant “micro switches” also known in this area as “Cherry switches” they are very cheap common water resistant switches, Mine came out of an old dish washer. I would imagine that just about everyone with a shop has a few of these lying around. I built a bracket out of a small piece of aluminum scrap and secured it and the switch to the handle bar support. I made a plug out of an aluminum bar scrap and made it into a movable trip, and installed it on my front brake cable. I adjusted it so that when I applied the front brake hard the switch would close, I then wired the switch to the CDI module to kill the motor. See the pictures.

What a huge difference it makes, I tried a test stop at the same speed as before and I stopped in a third of the distance. In fact I stopped in a shorter distance than I could with the clutch pulled in. The motors compression helps stop the bike when the ignition is killed. This is great !!!!

This entire upgrade took 30 Minutes to build and install, and it might save my butt someday. It is so simple that I am sure that I am not the first person to build this, But my search of the forum turned up nothing like it.

This set up could also be used to trigger a brake light.

Scott

[hill climber]

great job, emergence kill switch.

[NEAT TIMES]

You Are An Asset To The Forum.

[Dan]

Dang cleaver Sir

[Bikeguy Joe]

fo' sho'! That's thinking outside the box...or something like that.

[Dave31]

Great Ideal

[joe-craft]

Hey it a great idea, but im worried about the engine when that happens, wont the exess load of compression hurt the head and wont the clutch have some excess wear as well?

[eDJ]

I like the idea and the resourcefulness used to bring it to the finished stage. Sweet, simple, and Cheap.

On the "cherry" switch. If any of us were hunting for a switch like it while we scavenged thru old washers or dryers, about where would one of these be found. If we purchased one new would we ask for a "cherry switch" or is there a
proper name for it ? Could you post a photo of one ?

It's just my guess on killing a 2 cycle frame motor with a 6:1 compression ratio
that the engine would endure the demand of occasional emergency stops. It is afterall just for emergency conditions. As for clutch wear resulting from slippage from such stops I'd have to let others with more experience with these motors reply to that.

[Norman]

those are called micro switches and we use them at work on level controls to STOP compressors when the liquid gets either too low or too high. they are used in all kinds of operations I've seen them on aircraft landing gears used to keep the gear from retracting when there is weight on the gear and the gear up switch is accidnetly moved to the up position just one of the many places they are used. some are normaly open and some are normaly closed.
Norman

[Nomad]

That's a great idea, thanks for posting that..