Brakes

[michael769]

I would not agree that brakes destablise the car more the engine braking, since (as you mentioned) engine braking in none-all-wheel-drive cars retardates only one axle.

I would agree. I suspect that the mantra that brakes are less stable than engine is a hangover from the days (1970s and before) of poor quality drum brakes where consistency between the brakes was an issue. Modern disc brakes (and even the drum brakes used these days) are light years from that - assuming they are working well.

[trashbat]

Out of curiosity, does anyone know if the various stability systems (VSC, EBD etc) can apply the brakes to the wheels without any throttle or braking input present? i.e. on the overrun

[Ancient]

I'm a little confused: Are people interpreting "ease and squeeze acceleration" as 'engine braking' rather than as 'using acceleration sense' as I did? Or do people class all lifting off of the throttle with 'engine braking' so that we should either be on one pedal or the other (unless the clutch is down)?
Personally I will ease off for gradual decelaration in appropriate circumstances - uphill towards a car waiting to turn right, approaching the back of a motorway queue (whilst considering using brake lights only to inform those behind) etc... and use actual engine braking in preference to brake pads (i.e. select a 'flexible' gear which will hold my speed) on steep downhills (particularly long ones). Should I trail the brakes instead (contrary to the car handbook )?
Certainly I'm more likely to use brake pads on the approach to a roundabout for example, where I want to time entry to a gap with carrying the right speed to match the flow I am entering. Approaching red lights though, all options are available and I might just ease off in whatever gear I'm in if that will leave me with 'change and go' when it turns green. 'Brakes to slow' is just too prescriptive (and proscriptive too ) for my liking.

[akirk]

easing off might be that you lift your foot and let the cars mass / gravity / inertia (some complex physics thing ) slow the car down gradually...

engine braking might be driving up to a junction, and dropping down through the gears, letting the revs rise and the engine brake the car - it will slow the car down, but with a degree of stress on engine / transmission train v. wearing out disposable brake pads...

as posted above - sounds great with a sports car

Alasdair

[Astraist]

Out of curiosity, does anyone know if the various stability systems (VSC, EBD etc) can apply the brakes to the wheels without any throttle or braking input present? i.e. on the overrun

Yes, and they actually work best when the driver does not intervene with the pedals, mild understeer being the exception.

use actual engine braking in preference to brake pads (i.e. select a 'flexible' gear which will hold my speed) on steep downhills (particularly long ones). Should I trail the brakes instead (contrary to the car handbook )?

Actually, effective retardation on a downhil gradient fulfils the adage "brakes to slow". I usually slow down with the brakes before the downhill section to the desired speed. Once said speed is achieved, I downshift to the appropriate gear.

Unless the gradient is particularly steep, the appropriate gear usually allows me to drive down the gradient at a constant speed on the throttle. So it is still "brakes to slow, gears to go".

'Brakes to slow' is just too prescriptive (and proscriptive too ) for my liking.

And it is. Like I said earlier, heavy vehicles (heavier than seven tonns) will often require deceleration via sequental downshifting and additional retarders, in addition to foundation brakes.

[waremark]

Avoiding use of the brakes is not something to which I aspire. However 60 miles without braking evidences very good observation and forward planning.

I wonder about the relevance of this driving style to the OP's issues with other drivers. Does anyone else here try to avoid any use of the brakes, and if so can it be done without inconvencing other drivers?

[TripleS]

Avoiding use of the brakes is not something to which I aspire. However 60 miles without braking evidences very good observation and forward planning.

I wonder about the relevance of this driving style to the OP's issues with other drivers. Does anyone else here try to avoid any use of the brakes, and if so can it be done without inconvencing other drivers?

No, I don't seek to avoid all braking, but I do try to keep it to a minimum, subject to not causing inconvenience and irritation to others.

On the open road I normally try to lose speed for a bend by coming off the throttle early, and if I'm being followed I sometimes notice the other driver initially reducing his following distance, but almost invaraibly they seem to realise what I'm doing, and then accept it and return to a decent following gap. If anybody does look to be unhappy with what I do, and they show this by tailgating me, I'll change to a more conventional style until such time as they can overtake me. Harmony is thus restored quite soon.

[akirk]

A useful skill for those times when your brakes fail
We had this discussion when I joined the IAM in '98 and I did manage my morning commute the next day from SW Birmingham to nr. Coventry in rush hour / motorway / country roads / town driving without using brakes until I stopped... so it is definitely doable...
My conclusion from that - I am not sure it is a wise way to drive for a whole journey
- it changes the driving style to one focused on not using brakes rather than driving appropriately to the context
- it surprises other drivers as you make decisions they don't expect
- it probably still requires some form of braking (a la engine braking) so back to that debate

Would I use that as my style of driving = no. Is it a useful technique = yes. Should you aim to drive to not need brakes, but be happy to use them = yes.

Alasdair

[revian]

I've tried but for me (not universalizing) it is also this:

My conclusion from that - I am not sure it is a wise way to drive for a whole journey
- it changes the driving style to one focused on not using brakes rather than driving appropriately to the context

This may be more of a comment on my skill level than the technique itself...

I have a friend who is definitely an Advanced Driver (deliberately capitalized!) and I know he does it sometimes as practice

Ian

[Horse]

Don't multilple hazards , in a relatively short distance, sometimes require their individual braking phase?

I think neater, tidier, (pick your own adverb), driving is doing the least that is necessary, so would suggest coalescing the way you handle multiple close-together hazards can lower the work-load.

I've known it, for years, as 'grouping' hazards, so that your actions deal with them as a single hazard.

Also, there's a mantra used in the manufacturing industry of 'lean' - doing the bare minimum to achieve what you need. This applies in the motoring context, for example block changes rather than separate gear selection as you slow.

[Graham Wright]

Does anyone else here try to avoid any use of the brakes, and if so can it be done without inconvencing other drivers?

I play a little game on the commute to work. There is generally a queue of up to 20 cars ahead. There is no opportunity to overtake. I count the number of brake applications on the car in front looking for a record breaker. As tailgating rules, over a distance of around 1 mile, I have counted 80 applications on the car in front compared to my one.

Isn't it all to do with anticipation and judgement?

[TripleS]

Does anyone else here try to avoid any use of the brakes, and if so can it be done without inconvencing other drivers?

I play a little game on the commute to work. There is generally a queue of up to 20 cars ahead. There is no opportunity to overtake. I count the number of brake applications on the car in front looking for a record breaker. As tailgating rules, over a distance of around 1 mile, I have counted 80 applications on the car in front compared to my one.

Isn't it all to do with anticipation and judgement?

I suppose that accounts for most of it.

Most people seem to leave insufficient following distance, and I think that accounts for a lot of the braking. Driving in built-up areas is likely to make the avoidance of braking quite difficult, but on the open road I think very little braking should be necessary. Having said that, I am aware that some people in the advanced driving camp seem to like to see fairly free and firm use of the brakes. I'm not saying that's wrong, but it doesn't tally with the way I normally prefer to drive.

Anyhow, as a minor diversion, a recent topic on PH gave rise to the question of whether the transmission of acceleration and braking torque between a car wheel and the brake disc/hub assembly is catered for by the studs/nuts/bolts, or whether it is transmitted by the friction generated by the clamping force between the components. What's the answer?

Here is the thtread:

http://www.pistonheads.com/gassing/topi ... mid=106643

Do we have a suitable expert at hand to advise us, or are we dependent on SD for the answer?

Best wishes all,
Dave.

[Astraist]

Having said that, I am aware that some people in the advanced driving camp seem to like to see fairly free and firm use of the brakes. I'm not saying that's wrong, but it doesn't tally with the way I normally prefer to drive.

The only problem I have with firm braking (depends on just how firm) is that it might not be as effective in "gathering up" the traffic behind me, which I try to do when I am still in motion and not yet stopped.

By slowing down early and gently enough, I can build-up a queue behind me as a protection from being shunted from behind. The smaller the speed differential between me and those cars behind - the better.

[TripleS]

Having said that, I am aware that some people in the advanced driving camp seem to like to see fairly free and firm use of the brakes. I'm not saying that's wrong, but it doesn't tally with the way I normally prefer to drive.

The only problem I have with firm braking (depends on just how firm) is that it might not be as effective in "gathering up" the traffic behind me, which I try to do when I am still in motion and not yet stopped.

By slowing down early and gently enough, I can build-up a queue behind me as a protection from being shunted from behind. The smaller the speed differential between me and those cars behind - the better.

Yes, I agree with you: that also figures quite prominently in my thinking.

During my first couple of years driving, I was hit in the tail at least twice by people who failed to stop, even though I had not stopped in a hurried manner. Presumably they simply hadn't been paying attention, which is why I now seek to 'manage the speed reduction profile' of those behind me when I need to make a substantial reduction of speed, or I'm approaching a stopping point.