What exactly is "free wheeling"

"Freewheeling" is what you do on a bicycle when you stop pedaling, i.e. the drive wheel is disconnected from the power source when the rpm of the power source is lower than the rpm of the drive wheel.

This was common with two stroke engines as they were commonly lubricated by oil mixed with the fuel and coasting down a long hill would provide too little oil for the engine.

The freewheel was carried over by Saab to the earliest four stroke engines as many drivers liked to use it. My first car, a Saab 99 with the 1.7 liter engine, had a freewheel (located between the clutch and the gearbox) and I used it all the time as an automatic clutch. I used the clutch only for starting, stopping and an occational quick gear change. All other gear changes was done using the freewheel instead of the clutch. The freewheel was removed with the introduction of the 1.85 liter engine in the Saab 99. The more powerful engines was too much to handle for the freewheel.

Off-the-wall thought: Most U.S. states have laws forbidding free-wheeling. I wonder how the old Saabs with automatic free-wheeling conformed to this. Of course, there's also the question of how this prohibition was ever enforced...

Really? I've driven with freewheel for years & not known (or cared) about that. Why?

Well, there's a lever where you can lock it out, but what's the fun in that?

I can't imagine a scenario which would involve anyone caring about it. Hell, the cops aren't even allowed to pull people over for not wearing freaking _seatbelts_ in this state.

Dave Hinz

Nope, everybody I know that had two-stroke Saabs used the free-wheel. As Göran pointed out it was very practical as you only needed the clutch to start the car, to stop it you put in the neutral gear and just braked (a bit increase on the brake wear though). I was too young to drive one myself but I remenber the last 99 with free-wheel we had, a real beauty!

If they note that you are un belted, they will find another excuse

Malcolm

Don't know. But driving instructors will tell you that you have to be in a gear at all time. When I had UK driving lessons many years ago, I was told to approach each junction as: 5-change-4-change-3-change-2- change-1 and stop. It was a pain in the neck that I never practiced afterwards.

Sounds like reasonable advice if you're driving a fully-loaded

The laws against free-wheeling date back to the earliest days of the automobile. The thought was that you'd lose control of your vehicle if you were free-wheeling down a steep grade. Given the brakes of those days, it probably wasn't too far out of line with reality.

To enforce the law, however, the cop's going to have be sitting in your lap.

Apparently they don't teach that any more. Stick in 4th or 3rd until you're really slow then declutch. Like you do.

Personally, when approaching roundabouts with the possibility of a quick negotiation, I love

Graham

I recall that Waartburgs ( also 2 stroke ? ) had freewheeling hubs and Land Rovers used to have it as an option.

Graham

But I think that is different, more like a differential lock.

Years ago (late 1970s) I used a Ford Bronco that had the lockable front wheel hubs too.

-- MH

really slow then

negotiation, I love

Another peculiar official method that they teach at UK driving schools is shuffling the steering wheel. The idea is apparently that since you must have both hands at the steering wheel at all times, then it follows that the arms may be conflicting with each other if one of your hand is allowed to enter the other hand's territory. Again having reasonable strong arms, I find it easier to just wind the steering wheel round with one hand if necessary, this was also what I originally learned in DK. However, they sometimes show TV programmes here with real police chasing and I'm quite amazed to see the UK police drivers furiously shuffling the steering wheel when chasing villains.

Yes, this is also still taught in Australia. It's an absolute joke - far more dangerous as you can't get full wheel lock, or even close to it, in the time it takes to make a reasonable turn. The only person I know who actually drives like that is a friend who has not only been in more accidents than anyone I know - he has caused all of them. He looks like Mr Magoo when reversing out of a parking space or going around a round-about!!!

Starman from Oz

I think I'm missing something. I understand what the freewheel does -- it just eliminates engine drag -- but the procedure you just gave for coming to a stop is exactly what I do, and I have no freewheel.

-Aaron

Maybe a bit bad example, you're right, it's what I also do with a standard manual transmission. The point was that the clutch is only needed when you start the car.

It's illegal here in Australia too, for obvious reasons! Australia wasn't really a strong market for Saab's until the mid-70's so the 'free-wheeling' Saab's probably weren't an issue here.

Craig.

Wierd.. You'd have though US lawmakers would pull their heads out of the sane and make wearing seatbelts compulsory everywhere in the USA by now. I wonder if there are any uniform laws about the use and fitting of child-safety devices, harnesses and seats in cars in the US?

Wearing of seatbelts in cars is compulsory in all Australian states and territories. I saw my first seat-belt equipped bus yesterday too.

It's a very serious offence to be caught not wearing a seatbelt in a car (or small van/truck) here. The thing that bothers me more though is idiots who talk on hand-held cellphones while driving.... grrrr

The older C900's don't have drink holders or any easy way to install brackets for mounting mobile phones, GPS units, or other small electronic devices so it's probably a Good Thing in some respects since it reduces the temptation to be distracted by phones, or trying to hold a drink, while driving. But common-sense would tell you that it'd make sense to have devices available to make it more safe to use things like mobile phones while driving. I guess all the GM-built Saab's have drink holders and much easier ways to mount brakcets for phones, etc. than the pre-GM Saab's did.

The inverse ways that technology changes affect our driving habits is an interesting subject but getting outside the scope of the newsgroup. 8-) Feel free to carry it over to my C900 Workshop forums though....

Craig.

As I understood, the freewheel was provided on the two-strokes as on the overrun the engines were rather jerky, and so this got over the problem. The V4 95/96/97 used the same gearbox so got the freewheel by default. I am not sure why the early 99s used it but it disappeared as the power went up. We had a Saab 96 Sport 2-stroke, at home in the UK, great car, but only

Nope; one-way slip clutches are pretty robust when matched to the horsepower of the system. It requires you to "blip" the throttle a bit to bring it up to the gears, then go into it. If you stomp directly, it's jarring and probably bad for parts. But on the pre-oil-injected 2-stroke engines, it was mandatory because the lubrication came in through the carbs with the gasoline.