Freewheel Clutch: Lower RR
 

A cool technology of the 1950-60's national economy runs was the freewheel clutch.

The freewheel clutch was either attached to the transaxle or the wheel hub, only allowing power to be transmitted to the wheels in one direction. Like a ratchet, the wheels were driven when powered but freewheeled while gliding.

Most think of rolling resistance (RR) as being a quality of the tires and bearings, but it also encompasses friction from a spinning transmission and main clutch end. By using a freewheel clutch, you remove all the robbing friction from the axles inward.

The clutch seemed simple to design, just being a small freewheel hub you could probably pick up a McMaster-Carr spliced into an axle. You do lose reverse, but that's undesirable anyways...:)

- LostCause

This would not be as much of a problem on the jeep hurricane, that thing could spin and crab walk! :p Of course, dual engines is not really in the spirit of this forum

Was this technology ever used in production vehicles?

I saw a few videos a while back about a Saab Sonnet that was converted to electric.

It seemed to have a really nice range to it. If it had freewheeling, that may have been part of why the range was so decent.

http://www.diyelectriccar.com/forums...tage-9911.html

I think I'd rather have reverse along with injector shutoff.

I found this:
Free wheeling in your car

One of the comments claims that 1970's Saabs had a freewheel trans, until it was outlawed in the UK for safety reasons.

You can keep reverse but you have to place the freewheel clutch between the engine and trans. The down side is if you need the engine to slow you down it can't, that can be fixed if you get a locking overrun clutch (I think that is hat it is called maybe a sprag clutch check wiki). I believe the two other issues you can run into are noise and shock on the clutch. The shock would be if you are coasting and suddenly need to speed up as the engine will spin up quickly till it hits the speed of the clutch then it will have the sudden transfer of torque. I'm not sure how bad that will be but if the parts are strong enough it should be able to handle it.

One way / freewheel / sprag clutches are used in virtually every automatic transmission with the torque converter offering some shock absorbing characteristics.

Designing one to suit any car is simple enough and fitting is also straightforward.

I suggest locating it between the transmission out put and the final drive input so there is only one needed and fitting some sort of shock absorbing coupling (polyurethane?) is also reasonably simple.

just my 2c worth.

Peter.

The VW Lupo has a freewheeling 5th gear.

Only the Lupo 3L version has the freewheel in fifth gear ;).