Manual disengage for a centrifugal clutch

[stiletto2]

Originally Posted by dcb

Hmm, I wonder what happens if you have an engine brake with a centrifugal clutch? If you can get the engine to stop and if the clutch will still slip a little then the springs should pull the shoes back. Maybe? Break something? Maybe?

The centrifugal clutch will still hang on until the wheel speed slows enough. The thing is to get it to disengage enough to allow the engine rpm to drop enough so that it will not keep the clutch engaged.

It could "probably" be done. But maybe not a good or safe way to do it would be to grab the rear brake to lock it up with the throttle let off... the clutch might let go then and you could release the brake and continue to coast at what ever speed you managed to keep. ABS would defeat that idea though.

Using my scooter riding down hill with the throttle off, it would engine brake down to the point where the clutch would finally release. (about 10-12 mph) Then then bike would begin free wheeling and pick up speed. I'd have to blip the throttle to get the clutch to re-engage to keep from going too fast.

To make the idea work with a centrifugal clutch, there needs to be a way to disengage the shoes long enough for the engine rpm to come down to the point where it does not cause the clutch to stay engaged. Maybe push a lever that puts pressure on something to push the shoes in away from the clutch bell and at the same time applies some braking force to the variator to help reduce engine speed quicker. This action would only need to be temporary... just long enough to disengage the clutch and slow the variator enough to to where the clutch would stay disengaged. I know that's what needs to be done in simple terms, but I'm just another day dream engineer as well.

In the future, an electro-mechanical fluid could act as the engaging medium. There is already such a thing, but it is not practical (read WAY too expensive) at this point in time. Or possibly nonferrous clutch bell and magnetically activated/manipulated friction shoes. But by that time they might have anti-gravity all figured out... and who'd even want to ride a bike then?