BGOL

[Zebedee]

Oh no, somebody's said the PP thing. That's going to add another twenty pages to this thread!

[jcochrane]

A question...does it really matter that much whether separation, partial overlap or full overlap with H&T is used provided that the following three things are achieved?

1. In each case, after completing braking and gear change, the speed is the same at the same point on the road.
2. RPM is matched as required.
3. The same safety margin is maintained.

[Horse]

A question...does it really matter that much whether separation, partial overlap or full overlap with H&T is used provided that the following three things are achieved?

1. In each case, after completing braking and gear change, the speed is the same at the same point on the road.
2. RPM is matched as required.
3. The same safety margin is maintained.

It's all about terminology; 'brakes, then select appropriate gear', or: 'select lower gear for flexibility, then brake'. As long as you can use the appropriate terminology, you can explain anything away.

[TripleS]

A question...does it really matter that much whether separation, partial overlap or full overlap with H&T is used provided that the following three things are achieved?

1. In each case, after completing braking and gear change, the speed is the same at the same point on the road.
2. RPM is matched as required.
3. The same safety margin is maintained.

It's all about terminology; 'brakes, then select appropriate gear', or: 'select lower gear for flexibility, then brake'. As long as you can use the appropriate terminology, you can explain anything away.

You're talking my kind of language: I'm glad somebody does, if only occasionally.

Thanks for referring to appropriate gear rather than correct gear.

Best wishes all,
Dave.

[plumber]

I haven't been on the Forum in a while but seeing this thread has confirmed my belief in AD confusion. The op outlined the issue I had but in trying to get a sensible, clear WHY I was castigated by the AD Geeks who delight in accepting Dogma concerning Seperation, H & T and DDC all over the place with apparently smoothness and perfection. It is good to hear from some who have had diffiulties, it confirms it is not just me. Groups appear to be not very good at getting associates to understand what is wrong with Overlapping and WHY seperation is best. Much easier then to make associates feel small by dogmatically telling them and marking them down if they use it.

Whilst I have spent many hours doing the seperation equivalent of becoming ambidextrous I still hold the view of Seargent Gilbert and Vonhosen in that of itself is a perfectly safe and smooth method when planned for and applied correctly

[onlinegenie]

I haven't been on the Forum in a while but seeing this thread has confirmed my belief in AD confusion. The op outlined the issue I had but in trying to get a sensible, clear WHY I was castigated by the AD Geeks who delight in accepting Dogma concerning Seperation, H & T and DDC all over the place with apparently smoothness and perfection. It is good to hear from some who have had diffiulties, it confirms it is not just me. Groups appear to be not very good at getting associates to understand what is wrong with Overlapping and WHY seperation is best. Much easier then to make associates feel small by dogmatically telling them and marking them down if they use it.

Whilst I have spent many hours doing the seperation equivalent of becoming ambidextrous I still hold the view of Seargent Gilbert and Vonhosen in that of itself is a perfectly safe and smooth method when planned for and applied correctly

Hi Plumber.

I'm new here but having read through some threads before I joined I get the impression that you and I live near each other (Prescot in my case).

It's interesting that you refer to geeks who cannot explain why one style (not just BGOL) is preferred to another. When I passed my IAM test almost 31 years ago I went to an observer training evening where the examiner said almost exactly the same thing. He was aware of people who'd been presented for test having asked their observer why they should do something in a particular way and been told "Because that's the way we do it". Not a satisfactory answer!

As for BGOL, I've read an explanation as to why we should separate brake and gear. I'll quote it as close as possible to verbatim, but I've got quite a few advanced driving books and I can't remember which one this came from or how long ago I read it. "When the driver is braking, the car's weight is thrown forward and the car becomes, to an extent, unstable. If the driver disengages the clutch while the car is unstable it removes drive from the rear wheels and makes a skid more likely to occur."

I have to admit that the phrase "remove drive from the rear wheels" might just as well be written in a foreign language (although I'm sure many on this board will understand it) but I have always accepted this advice as a reason why BGOL should be avoided when possible. Please note those words "when possible"! At that same observer meeting the examiner talked about BGOL and how some test candidates were determined to avoid it at all costs. He mentioned a particular junction near where I live and pointed out that he always overlapped at that junction as it would be unsafe to attempt separation.

Finally on to your point "Much easier then to make associates feel small". You appear to have had a bad observer(s). I'm sorry to read that. When I was observing I always tried to explain things politely and explain why certain styles were preferred.

[sussex2]

If you accept that stability and control are what you are after then no BGOL in certain circumstances may improve both.
At other times and depending on the situation and vehicle it is not necessary and in my opinion can be self defeating.
Knowing when to use either method is part of the skill set someone who is dedicated to improving their driving should have.

Edited the last sentence to add 'Knowing when to use either method'....

[Silk]

Oh no, somebody's said the PP thing. That's going to add another twenty pages to this thread!

Shhhh! Nobody else has noticed yet - lets keep it that way.

@JC - No it doesn't matter in the slightest if you look at the outputs - it only matters to those who have an investment in the method by which the outputs are created.

I refer you back to my example of steering with knees - unless you're going to argue that it's an output, when it seems obvious to me that it's an input. If the methods that you use to steer, change gear and brake enable you to do it more efficiently/safer than other methods, then they are better inputs, are they not?

Good inputs produce good outputs, as far as I'm concerned. I don't see that it's possible to judge the ability or otherwise of a driver purely on outputs.

In order to avoid confusion, I'll give some examples of what I consider to be inputs and outputs: -

Inputs: Hands on the wheel, gearstick, handbrake, signals; feet on the pedals etc.

Outputs: direction, progress, smoothness and interaction with other road users/objects etc.

I'm not really sure where you would put the other stuff, such as: taking/using/giving information; sense of danger; hazard awareness etc. Are these inputs, outputs or none of the above?

[TripleS]

I've read an explanation as to why we should separate brake and gear. I'll quote it as close as possible to verbatim, but I've got quite a few advanced driving books and I can't remember which one this came from or how long ago I read it. "When the driver is braking, the car's weight is thrown forward and the car becomes, to an extent, unstable. If the driver disengages the clutch while the car is unstable it removes drive from the rear wheels and makes a skid more likely to occur."

Rather than saying that braking makes a car unstable, which sounds a bit worrying, I'd rather say it makes a car less stable, but it need not be a problem. Just how serious this is can only be judged in the light of the conditions in which we're braking. Light or moderate braking in a straight line on a dry road is unlikely to have any bad effects worth worrying about, largely because although there is an inevitable weight transfer onto the front tyres, they are sharing the load equally.

On the other hand, firm or hard braking on a downhill corner on a wet road is a very different matter, and that is the sort of thing where the risk of a skid is more likely, though still not inevitable. The difference here is the added factor that we're now in a cornering situation, which means that the front tyres are not sharing the load equally: the one nearest the outside of the curve will be more heavily loaded than the one near the inside of the curve. On top of all this, being on a wet road surface makes a skid more likely, but still not inevitable; it just means we need to take more care with our speed in the corner, and the amount of braking we use.

I have to admit that the phrase "remove drive from the rear wheels" might just as well be written in a foreign language (although I'm sure many on this board will understand it) but I have always accepted this advice as a reason why BGOL should be avoided when possible. Please note those words "when possible"! At that same observer meeting the examiner talked about BGOL and how some test candidates were determined to avoid it at all costs. He mentioned a particular junction near where I live and pointed out that he always overlapped at that junction as it would be unsafe to attempt separation.

The bit about "remove drive from the rear wheels" was presumably from a book written many years ago, as it seems to assume the use of a rear wheel drive car, and these days I imagine most cars have front wheel drive. In any case, in the situation we're talking about, i.e. braking, I wouldn't have thought that removing drive from the rear wheels would have any major effects. After all, if we're braking, it wouldn't be drive in the sense of power being applied, it would only be the braking effect of the engine, which is generally a small factor.

I don't know if that helps at all, but in any case you ought to consider what others have to say on the subject, and then see what you make of it all; so good luck.

By the way, if you do have any spins, (and you shouldn't really), nip back here and let us know what caused them.

Best wishes all,
Dave.

[waremark]

"As for BGOL, I've read an explanation as to why we should separate brake and gear. I'll quote it as close as possible to verbatim, but I've got quite a few advanced driving books and I can't remember which one this came from or how long ago I read it. "When the driver is braking, the car's weight is thrown forward and the car becomes, to an extent, unstable. If the driver disengages the clutch while the car is unstable it removes drive from the rear wheels and makes a skid more likely to occur."

I don't find that very convincing, nor even very relevant to brake gear overlap. Can you find the source of this explanation and quote from it more specifically?

It is certainly true that under braking, or even just engine braking, there is less weight on the rear wheels. If you enter a bend under braking, or just off the gas, the extra weight on the front wheels means that you have more grip at the front end than at the back. In most cars this would reduce understeer, and if speed is too high it could lead to oversteer. Oversteer is more likely if you lift off while already turning, or at the same time as steering sharply.

In a straight line, or at normal speeds in a bend, you can brake fairly firmly without loss of control. But at any speed I don't see why you would be less stable with the driven wheels disengaged than under engine braking.

[waremark]

Personally I don't agree that many of those make for tangible benefits, at least in a tame FWD car in ordinary conditions.

However I think you miss the biggest one, hinted at in 'fail safe'. That is, having to separate takes more time, so you have to brake earlier to accommodate it, so you have to plan earlier to accommodate that. We can all benefit from that, but especially associates, which is why I think it's an excellent teaching doctrine. Whether it's required so much beyond that, I'm less sure, but it's open to debate.

Since we are talking (well some of us are) about inputs and outputs, the relevant output is that if you have practised and perfected separation you are less likely to enter a bend too fast. Maybe.

[hir]

I refer you back to my example of steering with knees - unless you're going to argue that it's an output, when it seems obvious to me that it's an input. If the methods that you use to steer, change gear and brake enable you to do it more efficiently/safer than other methods, then they are better inputs, are they not?

Good inputs produce good outputs, as far as I'm concerned. I don't see that it's possible to judge the ability or otherwise of a driver purely on outputs.

Not too sure of your logic with this one. If good inputs produce good outputs [outcomes], as you assert, it must be possible to judge the ability of a driver purely on outcomes. From your point of view I would have thought your argument would be that the danger in assessing outcomes is that bad inputs may result in good outcomes and therefore to assess solely on outcomes would miss those bad inputs. But, that's not what you're saying.

The "knees" argument is specious. Nobody, but nobody, can use their knees to produce steering outcomes equivalent to the quality of steering outcomes achieved by using PP and/or fixed grip with hands. Therefore if a driver persistently used his knees to steer, his steering outcomes would never, could never, be as good as the steering outcomes of someone who used his hands and therefore the comparison is fallacious. By using the "outcomes" methodology for assessing the driver, the driver who used his "knees" would always be marked down by comparison. [Assuming, that is, he survived the attempt and didn't smash in to a tree on the first bend!]

In order to avoid confusion, I'll give some examples of what I consider to be inputs and outputs: -

Inputs: Hands on the wheel, gearstick, handbrake, signals; feet on the pedals etc.

Outputs: direction, progress, smoothness and interaction with other road users/objects etc.

I'm not really sure where you would put the other stuff, such as: taking/using/giving information; sense of danger; hazard awareness etc. Are these inputs, outputs or none of the above?

I think it's simpler than that.

There are only three things one can do with a car (stop sniggering at the back).
1. Make it go faster (accelerator)
2. Make it go slower (brake [or gears/engine braking for the great unwashed non-system anti-establishment unbelievers who are lurking out there])
3. Make it change direction (steering)

The "Inputs" are the actions that the driver uses to effect these three changes in the vehicle's state.

The "Outcomes" are the result/manifestation of the "Inputs" that are used to effect these three changes.

In the view of the proponents of an Outcomes based approach to the assessment of advanced driving ability it is the Outcomes that are of critical, primary, importance, not the inputs, which are of secondary importance. [That's not to say inputs are of no importance. An input might be so bad that it leads to a catastrophic Outcome... as in... "Please don't steer with your knees! Yes, I know this car's got air bags that would save us even if we crash landed on the moon! But, Oh! #%*'@+!"!!!#%". But, even in this extreme example, an assessment based on Outcomes would still be valid, it's just that the examiner may not survive the experience to mark the test sheet FAIL!]

[TripleS]

There are only three things one can do with a car (stop sniggering at the back).
1. Make it go faster (accelerator)
2. Make it go slower (brake [or gears/engine braking for the great unwashed non-system anti-establishment unbelievers who are lurking out there])
3. Make it change direction (steering)

1. Yes.
2.
3. Yes.

[onlinegenie]

"As for BGOL, I've read an explanation as to why we should separate brake and gear. I'll quote it as close as possible to verbatim, but I've got quite a few advanced driving books and I can't remember which one this came from or how long ago I read it. "When the driver is braking, the car's weight is thrown forward and the car becomes, to an extent, unstable. If the driver disengages the clutch while the car is unstable it removes drive from the rear wheels and makes a skid more likely to occur."

I don't find that very convincing, nor even very relevant to brake gear overlap. Can you find the source of this explanation and quote from it more specifically?

I'll try, but I've built up a collection of advanced driving books over the last 31 years and can't remember which one it's in (or even if I've still got it).