Separation of braking and gear changing - WHY?
Discussion
As someone who openly disagrees with the above being considered a pre-requisite for being considered a good driver, I ask the question:
Why should you completely finish braking for a hazard, losing all available torque from the engine, before engaging the gear for the job? Or to be more succinct - why must you not change gear whilst braking?
Why should you completely finish braking for a hazard, losing all available torque from the engine, before engaging the gear for the job? Or to be more succinct - why must you not change gear whilst braking?
scoobmeister said:
As someone who openly disagrees with the above being considered a pre-requisite for being considered a good driver, I ask the question:
Why should you completely finish braking for a hazard, losing all available torque from the engine, before engaging the gear for the job? Or to be more succinct - why must you not change gear whilst braking?
Why should you completely finish braking for a hazard, losing all available torque from the engine, before engaging the gear for the job? Or to be more succinct - why must you not change gear whilst braking?
Safest way for most drivers? Especially when they are asking much from their vehicle, assuming we are discussing Public Highway driving in this instance.
Those who may not consider all the circumstances and variables in any situation presented to them.
scoobmeister said:
As someone who openly disagrees with the above being considered a pre-requisite for being considered a good driver, I ask the question:
Why should you completely finish braking for a hazard, losing all available torque from the engine, before engaging the gear for the job? Or to be more succinct - why must you not change gear whilst braking?
Why should you completely finish braking for a hazard, losing all available torque from the engine, before engaging the gear for the job? Or to be more succinct - why must you not change gear whilst braking?
It isn't a pre-requisite for being a good driver.
It's a pre-requisite that you be able to do it for some driving tests.
One of the bonuses with it & why it's championed by some who teach it, is that as a by-product, it creates a large safety buffer by helping to ensure that too much speed isn't carried into hazards & that the vehicle will be well balanced on entry into the hazard.
Edited by vonhosen on Wednesday 21st March 22:12
scoobmeister said:
As someone who openly disagrees with the above being considered a pre-requisite for being considered a good driver
Not sure it is a pre-requisite of being considered a good driver. Just a pre-requisite as part of the "system". And even then it's not forbidden.
The system is designed to promote safety, smoothness and progress through (in addition to anticipation, planning, and all that good stuff) maintenance of maximum vehicle stability. The argument is that an overlap of braking and changing gear (or of more than one other "input" into the car - others being steering and throttle) compromises stability more than if those inputs are separated.
vonhosen said:
One of the bonuses with it & why it's championed by some who teach it, is that as a by-product, it creates a large safety buffer by helping to ensure that too much speed isn't carried into hazards & that the vehicle will be well balanced on entry into the hazard.
That's about the best explination I have heard for this. Kudos to you VH!
For me: it's always made the drive more smoother, forced me to plan ahead when driving and made ultimate sense.
Take roundabouts for instance.
If I can see that it's reletively clear (i.e. no queues at the exits and light traffic on the roundabout) then i'll probably approach it like this:
Extend vision onto and through the roundabout.
Position myself to enter my chosen lane/position myself to straight-line the roundabout (depending on situation/size/traffic flow).
Try to marry up my speed using acceleration sense and, if necessary, gentle application of the brakes so to time my approach to slot onto a gap on the roundabout.
In plenty of time, take a lower, more responsive gear; remembering to match revs.
Apply constant drive onto the obstacle and through the obstacle.
Firm up acceleration on the exit to the roundabout.
Take higher gear and settle into a cruising speed.
That's simplified, but it works for me. Banging on the brakes, taking a snatched gearchange down and then eventually stopping at the give way line does nothing for smoothness. Driving is like cooking - it's in the timing.
Just to add: I was always taught that when taking a lower gear, you should take a gear that offers you responsive feedback and a high degree of performance on the other side of the obstacle.
The smoothest, and ultimately most progessive, way of downchanging is to rev-match (either via a sharp blip of the throttle, or sustaining revs with the throttle). It's easier to match revs when your right foot isnt taken up with the brake duties.
Sure, people will moan about heel and toe; yet few people know how to accomplish this, and even fewer know how to do it properly and safely. Plus, I believe, there are few occasions on the roads where heel and toe would be adventageous, least of all necessary.
The smoothest, and ultimately most progessive, way of downchanging is to rev-match (either via a sharp blip of the throttle, or sustaining revs with the throttle). It's easier to match revs when your right foot isnt taken up with the brake duties.
Sure, people will moan about heel and toe; yet few people know how to accomplish this, and even fewer know how to do it properly and safely. Plus, I believe, there are few occasions on the roads where heel and toe would be adventageous, least of all necessary.
Thanks for all of your responses.
It was a loaded question of course. I was hoping for someone to suggest that downshifting while braking was inherently a "bad" thing for reasons of car balance... at which point I was hoping to mention automatic gearboxes and their own behaviour
However, you didn't... rats!
I agree it is a way of enforcing safety because it forces one to achieve hazard speed well before the hazard itself. However, I wonder how many drivers of automatics achieve hazard speed with the same margin of safety as someone driving a manual does due to the rules of system driving?
Perhaps it's my own intolerance of a very patronising IAM observer - who, although happy with my progress in all other respects, assured me some years ago that I would never make the grade until I adopted this particular aspect of the system - that I packed in the training with the feeling that the whole approach was very small minded; which is a shame, as I have always maintained an interest, and now find myself here trying to come to terms with it all again, and am beginning to suspect that my observer might have been a bit of a system evangelist....
Don't get me wrong - the observed runs helped me a great deal in roadcraft - I might have competed in motorsport for a few years, but that meant very little when it came to adopting the right attitude on the public roads.
However, I think the important philosophy behind these specific phases of the system is that the vehicle slows to the correct speed BEFORE entering the hazard, and not upon arrival. This philosophy shouldn't dicate HOW you bring the car into that state - that is an issue of car control, NOT roadcraft - IMHO!
It was a loaded question of course. I was hoping for someone to suggest that downshifting while braking was inherently a "bad" thing for reasons of car balance... at which point I was hoping to mention automatic gearboxes and their own behaviour
However, you didn't... rats!
I agree it is a way of enforcing safety because it forces one to achieve hazard speed well before the hazard itself. However, I wonder how many drivers of automatics achieve hazard speed with the same margin of safety as someone driving a manual does due to the rules of system driving?
Perhaps it's my own intolerance of a very patronising IAM observer - who, although happy with my progress in all other respects, assured me some years ago that I would never make the grade until I adopted this particular aspect of the system - that I packed in the training with the feeling that the whole approach was very small minded; which is a shame, as I have always maintained an interest, and now find myself here trying to come to terms with it all again, and am beginning to suspect that my observer might have been a bit of a system evangelist....
Don't get me wrong - the observed runs helped me a great deal in roadcraft - I might have competed in motorsport for a few years, but that meant very little when it came to adopting the right attitude on the public roads.
However, I think the important philosophy behind these specific phases of the system is that the vehicle slows to the correct speed BEFORE entering the hazard, and not upon arrival. This philosophy shouldn't dicate HOW you bring the car into that state - that is an issue of car control, NOT roadcraft - IMHO!
scoobmeister said:
Thanks for all of your responses.
It was a loaded question of course. I was hoping for someone to suggest that downshifting while braking was inherently a "bad" thing for reasons of car balance... at which point I was hoping to mention automatic gearboxes and their own behaviour
However, you didn't... rats!
I agree it is a way of enforcing safety because it forces one to achieve hazard speed well before the hazard itself. However, I wonder how many drivers of automatics achieve hazard speed with the same margin of safety as someone driving a manual does due to the rules of system driving?
Perhaps it's my own intolerance of a very patronising IAM observer - who, although happy with my progress in all other respects, assured me some years ago that I would never make the grade until I adopted this particular aspect of the system - that I packed in the training with the feeling that the whole approach was very small minded; which is a shame, as I have always maintained an interest, and now find myself here trying to come to terms with it all again, and am beginning to suspect that my observer might have been a bit of a system evangelist....
Don't get me wrong - the observed runs helped me a great deal in roadcraft - I might have competed in motorsport for a few years, but that meant very little when it came to adopting the right attitude on the public roads.
However, I think the important philosophy behind these specific phases of the system is that the vehicle slows to the correct speed BEFORE entering the hazard, and not upon arrival. This philosophy shouldn't dicate HOW you bring the car into that state - that is an issue of car control, NOT roadcraft - IMHO!
It was a loaded question of course. I was hoping for someone to suggest that downshifting while braking was inherently a "bad" thing for reasons of car balance... at which point I was hoping to mention automatic gearboxes and their own behaviour
However, you didn't... rats!
I agree it is a way of enforcing safety because it forces one to achieve hazard speed well before the hazard itself. However, I wonder how many drivers of automatics achieve hazard speed with the same margin of safety as someone driving a manual does due to the rules of system driving?
Perhaps it's my own intolerance of a very patronising IAM observer - who, although happy with my progress in all other respects, assured me some years ago that I would never make the grade until I adopted this particular aspect of the system - that I packed in the training with the feeling that the whole approach was very small minded; which is a shame, as I have always maintained an interest, and now find myself here trying to come to terms with it all again, and am beginning to suspect that my observer might have been a bit of a system evangelist....
Don't get me wrong - the observed runs helped me a great deal in roadcraft - I might have competed in motorsport for a few years, but that meant very little when it came to adopting the right attitude on the public roads.
However, I think the important philosophy behind these specific phases of the system is that the vehicle slows to the correct speed BEFORE entering the hazard, and not upon arrival. This philosophy shouldn't dicate HOW you bring the car into that state - that is an issue of car control, NOT roadcraft - IMHO!
It's a common fault with drivers (who are looking to drive to "the system" ) that when they drive automatics, they brake to the hazard rather than away (as they would in a manual when looking to make room for brake/gear seperation). I instruct them to brake in exactly the same way, because
1) you still want to be creating that safety buffer
2) Autos still need time to select a gear & settle prior to entry in order to be optimally balanced.
Infact in the auto you tend to be a little slower in than the manual, but quicker on the exit side.
The thing about a lot of advanced training is that it's competency based & the specified competencies will include you having to do things in certain ways. If you don't do it that way, then you don't pass that competency.
You may find HPC etc less prescriptive (but more expensive)
Edited by vonhosen on Wednesday 21st March 23:37
VH, I am interested in the approach which you recommend in an Auto. Why would you not use manual override to change down under braking? Effectively, this achieves the same as a heel and toe downchange in a manual vehicle, but without needing the same level of skill. I appreciate that you may be eliminating the safety buffer, but then the safety buffer is not imposed on the driver of a manual vehicle either unless there is an expectation of a gearchange.
scoobmeister, I think it's possible that your aversion to this aspect of the system is that you've possibly not received a very good demomstration of it in use. If you're ever in the northern half of the country, give me a shout, and I'll show you how system can work very well.
For me, there are three main benefits to the seperation of braking and changing gear and they've all already been mentioned. The most important one is that it promotes a planned approach to hazards, encouraging drivers to wait on the speed phase and not get ahead of themselves by getting a gear too early. Getting that gear early puts the driver in a "go" mindset, even though they might not have lost enough speed for the hazard. Waiting until the speed is right before selecting the gear prevents the driver from getting ahead of themselves.
The second major benefit of avoiding brake/gear overlap is that with your braking already completed for a hazard, your right foot is then free to adjust the engine revs to make a smoother downchange.
The third benefit is the consistency of approach that it encourages for any hazard. Whatever you need to negotiate, the system will accommodate it. If you do take an advanced test, consistent application of system and leaving yourself enough time to separate braking and changing gear demonstrates to the examiner that you're able to think ahead and plan your way through a situation, rather than just dealing with things as they happen.
For me, there are three main benefits to the seperation of braking and changing gear and they've all already been mentioned. The most important one is that it promotes a planned approach to hazards, encouraging drivers to wait on the speed phase and not get ahead of themselves by getting a gear too early. Getting that gear early puts the driver in a "go" mindset, even though they might not have lost enough speed for the hazard. Waiting until the speed is right before selecting the gear prevents the driver from getting ahead of themselves.
The second major benefit of avoiding brake/gear overlap is that with your braking already completed for a hazard, your right foot is then free to adjust the engine revs to make a smoother downchange.
The third benefit is the consistency of approach that it encourages for any hazard. Whatever you need to negotiate, the system will accommodate it. If you do take an advanced test, consistent application of system and leaving yourself enough time to separate braking and changing gear demonstrates to the examiner that you're able to think ahead and plan your way through a situation, rather than just dealing with things as they happen.
waremark said:
VH, I am interested in the approach which you recommend in an Auto. Why would you not use manual override to change down under braking? Effectively, this achieves the same as a heel and toe downchange in a manual vehicle, but without needing the same level of skill. I appreciate that you may be eliminating the safety buffer, but then the safety buffer is not imposed on the driver of a manual vehicle either unless there is an expectation of a gearchange.
The safety buffer is encouraged whether the gearchange is done or not, that is, look to get the speed right a good distance back from the point where you have to start to steer, in order that the vehicle can settle & you unhurriedly move from the brake to the accelerator (smooth transitions) prior to starting the steering. (When you are actually having to take the gear with brake/gear seperation, it just forces the issue more, with the candidate more easily aware of & able to identify how late they are with the system.)
As for the manual override bit. If you drive it in manual mode then you aren't strictly using it as an auto. One of the benefits of the auto use, is the ability to always have both hands on the wheel (particularly under braking). My favoured approach with autos (whether to use manual/tiptronic or auto) will be dependent on the particular implementation of the box by the vehicle's manufacturer, as they can differ greatly.
Whichever method I use though, remaining unhurried in my driving will still be a priority, as will creating the safety buffer, balancing the vehicle & being on the accelerator on entry.
Edited by vonhosen on Thursday 22 March 07:01
razerwire said:
scoobmeister said:
at which point I was hoping to mention automatic gearboxes and their own behaviour
I always thought an autobox does its gear changing when you apply the gas.
Most do. There are exceptions. Audi even have a system that detects if you are cornering and holds onto the current gear until you have straightened up - even if you push the loud pedal.
Those systems that are a computer controlled manual clutch can and do downchange under braking if the user pulls the paddle on the steering column but the computer matches the engine revs to road speed perfectly avoiding any interruption to drive that might destabilise the car. Fascinating system - never driven one - I'm looking forward to a go.
Flappy paddle computer rev-matching jobbies are designed pretty much to mitigate any undesirable effects of overlapping gear changing with braking (via rev matching) or gear changing and steering (both hands still on wheel).
Got to wonder why they go to all that trouble, eh?
Edited by Don on Thursday 22 March 07:47
I brake and change gear at the same time in my car, but it's a relatively stable fwd with a small engine, however it can still be made unstable if the mix of foot brake and engine brake is too high all of a sudden.
I'm sure driving a Griff 500 around would make you see benefit of sperated braking and gear changing!?
So far when I do try it, I brake, but hold the gear, when the revs drop too far I clutch, while still observing for correct gear when I release the brake, bring the clutch up with a blip of the revs and smoothly away again
I've found it the hardest work and the least benefit (that I can see anyway) for my driving (probably to do with my car) so I haven't taken it up, but I can see the benefits... all the other stuff on here has made sense so far
I would like to pick it up enough to be totally comfortable with it.
Dave
I'm sure driving a Griff 500 around would make you see benefit of sperated braking and gear changing!?
So far when I do try it, I brake, but hold the gear, when the revs drop too far I clutch, while still observing for correct gear when I release the brake, bring the clutch up with a blip of the revs and smoothly away again
I've found it the hardest work and the least benefit (that I can see anyway) for my driving (probably to do with my car) so I haven't taken it up, but I can see the benefits... all the other stuff on here has made sense so far
I would like to pick it up enough to be totally comfortable with it.
Dave
Mr Whippy said:
I would like to pick it up enough to be totally comfortable with it.
Dave
Its quite straightforward with a bit of forward planning and practice. To be honest it wasn't the hardest thing I found about doing an Advanced Test....or the be all and end all of it either. Far harder was being completely "systematic" about every hazard and really making myself consider each phase properly with the proper level of observation and planning to be able to do so.
The gear/brake thing is often easiest to master with some help from someone who can do it (Observer) just reminding you - "brake now", "no more braking get the speed right", "ok - smoothly off, and clutch in, take up gear", "little bit of throttle to smooth it out , clutch up now" etc etc. The talking through the whole thing really helps with the timing.
Once you've done it enough you can choose to overlap or NOT overlap at will. Its also (once Advanced Test passed and taken care of) fun to practice up the twinkletoes business of left foot braking, Heel and Toe and even double-de-clutch (not strictly necessary).
All the above a good hoot and everything but the bit that matters is the observation and planning that happens first IMO.
I think that the bit that associates find hardest, before we even get to separation, is scrubbing sufficient speed before the hazard. So many people are still on the brakes halfway round a corner that I'm convinced that they simply don't have the forward planning ability to know how much speed they have to kill until they're right on top of it. The number of times I find myself saying "Brake. Harder. Harder!" Give them a target to achieve their desired speed by (say, a lamppost) and they still can't do it, because they can't foresee the appropriate speed in time. They always over-estimate how fast they can take the hazard and end up scrubbing a bit more too late. It all gets so much easier when their observation skills have improved to the point where they can judge the correct amount of slow down from a good distance away.
Mr Whippy said:
I brake and change gear at the same time in my car, but it's a relatively stable fwd with a small engine, however it can still be made unstable if the mix of foot brake and engine brake is too high all of a sudden.
I'm sure driving a Griff 500 around would make you see benefit of sperated braking and gear changing!?
I'm sure driving a Griff 500 around would make you see benefit of sperated braking and gear changing!?
I managed to demonstrate the problems with not separating the breaking, gear change and turn in particularly embarrasing manner at silverstone a few years ago. Managed to exit copse backwards at 80ish having made a complete hash and locking the back wheels...
Certainly showed me why one leaves a decent error margin and drives nowhere near the limits under normal conditions on the road...
On a road I frequent there is a very tight, blind, hedge all round the inside, left hand 90deg.corner. I can't help thinking that, having slowed to be able to stop in the distance I can see,it is still too fast, when another car or worse lorry cutting the corner, causes me to want to stop suddenly, particularly so if the space I have left is compromised by the other vehicle.
My point is I really prefer to come into the corner just on, or at least covering, the brake until I can see it to be clear. This I know does not tally with the "balanced approach"
What do you think?
My point is I really prefer to come into the corner just on, or at least covering, the brake until I can see it to be clear. This I know does not tally with the "balanced approach"
What do you think?
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