IAM avoidance of brake/gear overlap going down steep hills?!

[RobM77]

I don't wish to start a huge thread on this one again I heel and toe everywhere for my own good reasons (as many others here do), but hired a Fiat Panda on holiday in Kefalonia for two weeks and couldn't heel and toe mainly because of the extreme driving position and to some extent the sensitivity of the brake pedal. This was a great opportunity to try out the IAM method of corner/hazard approach and BGOL avoidance for two weeks, which I was interested in after a recent thread on here about it. I got on just fine in most scenarios braking first and then selecting the appropriate gear, although obviously I'd rather be using H&T. My problem came with downhill bends, more specifically the endless hairpins you get when descending a mountain. These hairpins required 2nd gear at circa 20mph, and were often approached in 3rd or 4th at 30-40mph. If I used the IAM method, when I came off the brake to change gear gravity would accelerate the car rapidly (cue screaming girlfriend!), which was lurchy, a wee bit dangerous and it what's more it took me out of scope for 2nd gear! I couldn't see any way round it and was forced to use the numpty approach of just selecting 2nd gear and letting the clutch out carefully (cringe!). I wasn't keen on this with 1km drops at the edge of gravel strewn roads, so what's the IAM approach to this? Obviously in my Elise or BMW it wouldn't be an issue, I'd keep the brake on to keep speed down and select the next gear with a H&T rev match, like I do everywhere anyway.

[Vaux]

RobM77 said:

I don't wish to start a huge thread on this one again

Clearly.

RobM77 said:

.....so what's the IAM approach to this? ....

Is it impolite on here to say RTFM?

Roadcraft (latest edition) page 69.

Overlapping is allowed.

[tenohfive]

Vaux said:

RobM77 said:

I don't wish to start a huge thread on this one again

Clearly.

RobM77 said:

.....so what's the IAM approach to this? ....

Is it impolite on here to say RTFM?

Roadcraft (latest edition) page 69.

Overlapping is allowed.

In that exact set of circumstances only, when driving downhill it is accepted that out of necessity there will be an overlap. Otherwise Roadcraft forbids it.

[Vaux]

tenohfive said:

In that exact set of circumstances only, when driving downhill it is accepted that out of necessity there will be an overlap. Otherwise Roadcraft forbids it.

No it doesn't.

[BertBert]

tenohfive said:

In that exact set of circumstances only, when driving downhill it is accepted that out of necessity there will be an overlap. Otherwise Roadcraft forbids it.

Utter twaddle. There is no such thing in Roadcraft as forbid. Whether it's specifically from Roadcraft or what the IAM or Rospa publish, it is very clear that the System presented is based on safety first. Then it goes on to detail the various methods that have been developed to maximise safety in various circumstances. It clearly says that going downhill is a clear exception to the normal method of avoiding brake/gear overlap.

HOWEVER it also says that in *any* circumstance that brake/gear overlap reduces safety it should not be used.

Bert

[Strangely Brown]

Vaux said:

RobM77 said:

I don't wish to start a huge thread on this one again

Clearly.

RobM77 said:

.....so what's the IAM approach to this? ....

Is it impolite on here to say RTFM?

Roadcraft (latest edition) page 69.

Overlapping is allowed.

Quite.

Rob, you have been involved in enough discussion on the subject here and have had it explained to you in as many different ways as it is possible to explain it. That being the case there is no point in getting involved to repeat it all this time.

As Vaux says, RTFM.

Edited by Strangely Brown on Sunday 2nd August 16:41

[RobM77]

Sorry chaps. I have read all the threads on here, and rather than just referring to a book, I was interested in people's opinions. The only way I could see the gearchange being safe would be to heel and toe. In a car where it's not possible, I guess you just have to really gently let the clutch out? It's new to me because I don't often drive cars where heel and toe isn't possible.

[james_gt3rs]

RobM77 said:

The only way I could see the gearchange being safe would be to heel and toe. In a car where it's not possible, I guess you just have to really gently let the clutch out? It's new to me because I don't often drive cars where heel and toe isn't possible.

But not matching the revs isn't usually unsafe, unless you have a TVR or something, it's just a less desirable thing to do.

[RobM77]

james_gt3rs said:

RobM77 said:

The only way I could see the gearchange being safe would be to heel and toe. In a car where it's not possible, I guess you just have to really gently let the clutch out? It's new to me because I don't often drive cars where heel and toe isn't possible.

But not matching the revs isn't usually unsafe, unless you have a TVR or something, it's just a less desirable thing to do.

Well, it's obviously less safe than matching revs, but I think your point is that the difference is neglible. I suppose coming from a racing and RWD background I'm imagining it to be less safe than it really is. Made me a bit twitchy not H&Ting with those steep drops and gravel on the road though!

[Vaux]

RobM77 said:

Sorry chaps. I have read all the threads on here, and rather than just referring to a book, I was interested in people's opinions.

No, you asked,

RobM77 said:

so what's the IAM approach to this?

The IAM doesn't use Roadcraft as its training book (although it will sell you one via its website), but its driving method is based on Roadcraft and the Information-Position-Speed-Gear-Acceleration system of car control.

The IAM new book is called “How to be a better driver” and has the following advice (that I could find):

Pg 24 “Once you’re travelling at the right speed to negotiate the hazard, select the correct gear. (In some circumstances, you may need to change gear just before you finish braking.)

Pg 52 “Keep every drive as simple as possible by not overlapping braking, steering and gear inputs. However, if driving conditions force you to do so, always overlap a gear change with braking, not steering as that would mean taking a hand off the wheel.”

Pg 57 “Examiner Checklist: Does the driver avoid overlapping gear, brake and steering inputs?”

I believe this is consistent with the Roadcraft philosophy of avoiding brake and gear overlap, except in certain situations. It doesn't spell out the situations as clearly as Roadcraft though.

[jaf01uk]

There are a couple of options available in this situation, the roadcraft manual does not say you cannot overlap, it says that if it is necessary on downhills or planned it is fine, there is also the option to slow a few mph extra then do a sustained rev/blip of throttle gearchange - the car would only gain speed back to what you wanted it to be in the first place,
Gary

[tenohfive]

BertBert said:

tenohfive said:

In that exact set of circumstances only, when driving downhill it is accepted that out of necessity there will be an overlap. Otherwise Roadcraft forbids it.

Utter twaddle. There is no such thing in Roadcraft as forbid. Whether it's specifically from Roadcraft or what the IAM or Rospa publish, it is very clear that the System presented is based on safety first. Then it goes on to detail the various methods that have been developed to maximise safety in various circumstances. It clearly says that going downhill is a clear exception to the normal method of avoiding brake/gear overlap.

HOWEVER it also says that in *any* circumstance that brake/gear overlap reduces safety it should not be used.

Bert

Care to point out the section where it suggests another time when you can use the brake/gear overlap other than when going downhill?

Because thats the only one I can recall. Yes, it doesn't forbid it - but it doesn't suggest any other scenario when it would be appropriate iirc.

Edited by tenohfive on Sunday 2nd August 21:49

[BertBert]

Without any great searching, in ch 4 it says that "Sometimes it is helpful to overlap braking and with the gear change."

It is very clear that it is not being prescriptive about those circumstances. However there are 3 examples:

-Low speed left and right turns with a vehicle close behind (pic shows 90 degrees)
-sharp left or right turns with a vehicle close behind (pic shows >90 degrees)
-going downhill

HTH, time for a refresh?
Bert

[RobM77]

Vaux said:

RobM77 said:

Sorry chaps. I have read all the threads on here, and rather than just referring to a book, I was interested in people's opinions.

No, you asked,

RobM77 said:

so what's the IAM approach to this?

Sorry, maybe I didn't word that quite right. There's a definite group of people on here who say that one shouldn't overlap brakes and gears, and I was just interested in their opinions, because not all cars allow it and I'm not experienced in driving such cars, but sometimes I have to!

[jaf01uk]

tenohfive said:

BertBert said:

tenohfive said:

In that exact set of circumstances only, when driving downhill it is accepted that out of necessity there will be an overlap. Otherwise Roadcraft forbids it.

Utter twaddle. There is no such thing in Roadcraft as forbid. Whether it's specifically from Roadcraft or what the IAM or Rospa publish, it is very clear that the System presented is based on safety first. Then it goes on to detail the various methods that have been developed to maximise safety in various circumstances. It clearly says that going downhill is a clear exception to the normal method of avoiding brake/gear overlap.

HOWEVER it also says that in *any* circumstance that brake/gear overlap reduces safety it should not be used.

Bert

Care to point out the section where it suggests another time when you can use the brake/gear overlap other than when going downhill?

Because thats the only one I can recall. Yes, it doesn't forbid it - but it doesn't suggest any other scenario when it would be appropriate iirc.

Edited by tenohfive on Sunday 2nd August 21:49

I don't have an up to date RC as we use a bdised version of our own for training now but from recollection if for example there is a car parked in front of a left turn it was acceptable to combine the speed and gear phase to get it fitted in as long as it was planned from the start, ie. "speed and gear phase will be combined dictated by stationary obstruction prior to turn"
Gary

PS, I think the point the OP is trying to make/labour is that the system is not flexible but MUST be followed to the letter which of course couldn't be further from the truth.

[Strangely Brown]

RobM77 said:

Vaux said:

RobM77 said:

Sorry chaps. I have read all the threads on here, and rather than just referring to a book, I was interested in people's opinions.

No, you asked,

RobM77 said:

so what's the IAM approach to this?

Sorry, maybe I didn't word that quite right. There's a definite group of people on here who say that one shouldn't overlap brakes and gears, and I was just interested in their opinions, because not all cars allow it and I'm not experienced in driving such cars, but sometimes I have to!

That's not quite true, Rob. OK, well maybe there are a couple but they have missed the point too. The majority of Roadcraft trained drivers on here do not say that you shouldn't overlap brakes and gears, rather they say that 99.9% of the time it is simply not necessary... and in any case there are other advantages to separation.

[RobM77]

Strangely Brown said:

RobM77 said:

Vaux said:

RobM77 said:

Sorry chaps. I have read all the threads on here, and rather than just referring to a book, I was interested in people's opinions.

No, you asked,

RobM77 said:

so what's the IAM approach to this?

Sorry, maybe I didn't word that quite right. There's a definite group of people on here who say that one shouldn't overlap brakes and gears, and I was just interested in their opinions, because not all cars allow it and I'm not experienced in driving such cars, but sometimes I have to!

That's not quite true, Rob. OK, well maybe there are a couple but they have missed the point too. The majority of Roadcraft trained drivers on here do not say that you shouldn't overlap brakes and gears, rather they say that 99.9% of the time it is simply not necessary... and in any case there are other advantages to separation.

Fair enough, I must have mis-understood. I must confess, try as I might, I couldn't find a way to drive the little Panda that felt as satisfying as braking for corners and hazards whilst changing gear smoothly as I would in one of my cars.

By the way, when I drove the Panda I had no idea it retailed for £4995. What an absolute bargain! Ok, you'll need legs two feet shorter than mine to get comfortable, but the ride was pretty well judged, the handling perfectly adequate, and amazingly it fitted my girlfriend's suitcase (which I fit in!) and mine without a problem, and don't tell the hire company, but we even drove it 8km up a totally unmade road up a 1700m mountain without so much as a rattle. Really great value car!

[BertBert]

RobM77 said:

There's a definite group of people on here who say that one shouldn't overlap brakes and gears, and I was just interested in their opinions

I think that most of the people you refer to agree that not overlapping is a core technique that they find a good technique. I doubt that many of them will actually claim it as an absolute, overriding all else!

One way of looking at it is that the ability to change gear smoothly whilst applying the brakes is yet another important skill in the armoury of the Advanced Driver! Of course it should be doable with and without rev matching. All should be brought into play at the appropriate time.

Bert

[RobM77]

BertBert said:

RobM77 said:

There's a definite group of people on here who say that one shouldn't overlap brakes and gears, and I was just interested in their opinions

I think that most of the people you refer to agree that not overlapping is a core technique that they find a good technique. I doubt that many of them will actually claim it as an absolute, overriding all else!

One way of looking at it is that the ability to change gear smoothly whilst applying the brakes is yet another important skill in the armoury of the Advanced Driver! Of course it should be doable with and without rev matching. All should be brought into play at the appropriate time.

Bert

Thanks. I guess based on that my holiday was good practise in changing down without using the throttle . It felt weird at first, letting the clutch up without rev matching felt as strange as breathing whilst underwater or something I got used to it, but was very glad to get back to my Lotus and BMW in England. It's good to keep driving like that in practise though, for when you need to drive a car which doesn't permit H&T.

[jaf01uk]

RobM77 said:

BertBert said:

RobM77 said:

There's a definite group of people on here who say that one shouldn't overlap brakes and gears, and I was just interested in their opinions

I think that most of the people you refer to agree that not overlapping is a core technique that they find a good technique. I doubt that many of them will actually claim it as an absolute, overriding all else!

One way of looking at it is that the ability to change gear smoothly whilst applying the brakes is yet another important skill in the armoury of the Advanced Driver! Of course it should be doable with and without rev matching. All should be brought into play at the appropriate time.

Bert

Thanks. I guess based on that my holiday was good practise in changing down without using the throttle . It felt weird at first, letting the clutch up without rev matching felt as strange as breathing whilst underwater or something I got used to it, but was very glad to get back to my Lotus and BMW in England. It's good to keep driving like that in practise though, for when you need to drive a car which doesn't permit H&T.

You can still rev match, all you do is lose a couple extra mph and do a sustained rev/blipped gearchange, no fuss no drama and no extra time needed either!