Manual disengage for a centrifugal clutch

[The Atomic Ass]

Originally Posted by dcb

It does no such thing. You can ride a three wheeler on two wheels, you can ride a 4 wheeler on two wheels. Put training wheels on your bike and balance on one of them to coast (have fun in the corners)

Been there, done that. It won't stay up on either side wheel.

Aside from that the trike kit sucks. It's strictly a winter attachment.

[dcb]

Originally Posted by The Atomic Ass

Been there, done that. It won't stay up on either side wheel.

Well, that's a personal problem, not a physics problem

Anyway, maybe bodger up a real clutch instead of the centrifugal one, or freewheel/sprag on the other end of that rod connected to the bellhousing, or in the rear wheel hub, whichever looks easiest to engineer.

A real clutch would be ultimately more efficient than a freewheel though since you don't have to use the starter as much and can bump start if you time the traffic obstructions right.

[Ptero]

A real clutch would be ultimately more efficient than a freewheel though since you don't have to use the starter as much and can bump start if you time the traffic obstructions right.

I entirely disagree. Because there is no neutral with a CVT or CC, a real clutch (as compared to a freewheeling sprag clutch) would require the operater to hold the clutch in for the duration of the glide. As I have pointed out in other posts, the throw-out bearing is sealed, without provision for cooling. It is not designed for long periods of operation, which increases the liklihood if failure.

A sprag clutch, on the other hand, allows instantaneous coasting whenever the throttle is backed off. Obviously, a gentle matching to regain drive force will have to be practiced by the operator to prevent damage to the sprag clutch or stressing of drive components. Still, for hypermiling applications, I can think of nothing better.

[dcb]

Originally Posted by Ptero

I entirely disagree.

With P&G/EOC you don't usually overrun the engine, even with a clutch. And where the clutch gains an edge is in the area of engine restarting (and reliability), better to use your momentum directly than through an alternator through a battery through an electric motor. Not a huge gain on efficiency but enough to put it ahead in skilled hands.

[Ptero]

I see no advantage for a manual clutch in hypermiling with a CVT.

The charging system of a vehicle is constantly charging the battery untill it is charged to full capacity. Why would you want to start the engine if you were coming to a stop? I will stick with electric start and use it when I need to go when the light turns green.

With a freewheeling sprag clutch, it may be better to allow a motorcycle engine to idle between power pulses rather than shut it off then turn it on again, regardless of method. I suspect smaller engines fall more easily away from stochiometric fuel ratio than larger ones. This suggests there is a difficulty in realizing measurable mpg gain by turning off the engine for short intervals because you are likely to operate in a rich condition when restarting whereas you would have been maintaining a lean condition if you had simply idled.

For longer distance coasting, shutting down the engine is optimal.

Overrunning an engine has not been discussed so I have no idea what you are talking about. An overrunning clutch is a type of sprag clutch. It is the one to use in this application.

[dcb]

Originally Posted by Ptero

Why would you want to start the engine if you were coming to a stop?

I use my momentum to start the engine many many times per trip where I don't have to come to a complete dead stop (or if I see that I will be taking off right away). Really any time I need to slow down at all the engine is off and I usually have enough momentum to relight it when there is room to run again. Again, many many times per trip. I usually get over 70mpg in a metro around town, a smart can't do that even in the most experienced hands. It has a not-so-smart driveline and a clutch would be a big improvement (as would a ratio selection lever, or just plain gears for efficiencies sake).

[Ptero]

Manual disengage for a centrifugal clutch
Uh, I'm talking about mounting a sprag clutch on a motorcycle with a CVT...

[dcb]

Well, cvt seems to be a limiting factor. My 6 speed bike gets about 100mpg with mostly technique.

[The Atomic Ass]

Both idea's are possible, but I'm not sure which is the easiest to do. It would seem like the over-running clutch, if one could be had as small as the spline adapter that is currently on my clutch drum, would make for an easier (if welding required) solution.

OTOH, being able to bump-start would be equally nice, so replacing the existing assembly with a manual job would also be a nice adaption, as well as the ability to go BELOW 15mph, which I run into a fair amount of these days. But it would have to have some kind of externally cooled throw-out bearing as the bike will coast literally for miles given good conditions.

Either option requires planning, and machining, and thinking, which I'm hesitant to do simply out of sheer laziness.

[Ptero]

Here's the thinnest overrunning clutch I've found.
http://universalpartsinc.trustpass.a...ext=overriding