Braking queries

Author
Discussion

Scott OSRS

Original Poster:

31 posts

30 months

Saturday 4th February 2023
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I know you should be using three phase braking, but I’m not too sure how firm the middle phase should be eg for a regular roundabout on a 30 or 40 road? You could obviously be really light, but that would mean braking for ages in advance, or you could be nearly at threshold, but that might not be the most comfortable for passengers. Just wondering what the sort of “acceptable” point is.

Another thing I wasn’t too sure about is how long the feather-on phase should be. Is it acceptable to just blend this into the middle phase, such that from the moment you put your foot on the brake pedal you slowly squeeze it down at the same rate of pressure from no braking until you reach the desired level of braking, or should you pause for a couple of seconds when you feel the brakes first come on prior to then continuing to squeeze it further in the middle phase?

Sorry I know this is very basic stuff but I’ve read conflicting things online - some saying you should be braking early and light as it’s safer and nicer on the brake pads, others saying you should be braking firmly to make good progress.

Edited by Scott OSRS on Saturday 4th February 18:46

Haltamer

2,455 posts

80 months

Saturday 4th February 2023
quotequote all
You predominantly sense the rate of change in acceleration rather than acceleration itself.

E.g., If you are going to brake "heavily", gently build up to the pressure - For lighter braking, this blend period can be shorter.

Within the realms of being sensible (Due regard for grip, not being rear ended etc.) it's relatively up to you in my opinion - What feels comfortable, and what is appropriate for the drive you're on? - Transporting fabrége eggs might lead to a generally more wafting brake.

Have a watch of Reg Local's braking video if you haven't already!

waremark

3,242 posts

213 months

Saturday 4th February 2023
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Scott OSRS said:
I know you should be using three phase braking, but I’m not too sure how firm the middle phase should be eg for a regular roundabout on a 30 or 40 road? You could obviously be really light, but that would mean braking for ages in advance, or you could be nearly at threshold, but that might not be the most comfortable for passengers. Just wondering what the sort of “acceptable” point is.

Another thing I wasn’t too sure about is how long the feather-on phase should be. Is it acceptable to just blend this into the middle phase, such that from the moment you put your foot on the brake pedal you slowly squeeze it down at the same rate of pressure from no braking until you reach the desired level of braking, or should you pause for a couple of seconds when you feel the brakes first come on prior to then continuing to squeeze it further in the middle phase?

Sorry I know this is very basic stuff but I’ve read conflicting things online - some saying you should be braking early and light as it’s safer and nicer on the brake pads, others saying you should be braking firmly to make good progress.

Edited by Scott OSRS on Saturday 4th February 18:46
Not basic stuff at all! And there is no right answer to any of this. Something a wise coach once said to me about one drive was: 'the braking was a bit firm for the pace of the drive'. So in my model of good driving, I would be braking more gently from 30 or 40 than I would from 60 or 70. And I think the term 3 phase braking is a misnomer. I think the best result is a progressive increase in braking force, perhaps a plateau at the top, and then a progressive reduction in braking force.

Veryoldbear

218 posts

104 months

Tuesday 7th February 2023
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It all comes down to
"Don't spill the coffee" and "don't frighten the passengers"

waremark

3,242 posts

213 months

Tuesday 7th February 2023
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waremark said:
Not basic stuff at all! And there is no right answer to any of this. Something a wise coach once said to me about one drive was: 'the braking was a bit firm for the pace of the drive'. So in my model of good driving, I would be braking more gently from 30 or 40 than I would from 60 or 70. And I think the term 3 phase braking is a misnomer. I think the best result is a progressive increase in braking force, perhaps a plateau at the top, and then a progressive reduction in braking force.
P.S. Ideally passengers would not notice either the beginning or end of the braking. An illustration in Roadcraft (p 111 in 2020 edition) shows a progressive increase in braking force to one-third of the braking distance, followed by a reduction in braking force over a longer distance. I generally take longer to get to peak braking force, and often make subtle changes in pressure to achieve a suitable speed where it is needed.

Scott OSRS

Original Poster:

31 posts

30 months

Saturday 11th February 2023
quotequote all
Thanks for the replies all.

Haltamer said:
You predominantly sense the rate of change in acceleration rather than acceleration itself.

E.g., If you are going to brake "heavily", gently build up to the pressure - For lighter braking, this blend period can be shorter.

Within the realms of being sensible (Due regard for grip, not being rear ended etc.) it's relatively up to you in my opinion - What feels comfortable, and what is appropriate for the drive you're on? - Transporting fabrége eggs might lead to a generally more wafting brake.

Have a watch of Reg Local's braking video if you haven't already!
Thanks for the recommendation, I've started watching his series.

waremark said:
Not basic stuff at all! And there is no right answer to any of this. Something a wise coach once said to me about one drive was: 'the braking was a bit firm for the pace of the drive'. So in my model of good driving, I would be braking more gently from 30 or 40 than I would from 60 or 70. And I think the term 3 phase braking is a misnomer. I think the best result is a progressive increase in braking force, perhaps a plateau at the top, and then a progressive reduction in braking force.
I agree with the part in bold, I've found that too.

waremark said:
P.S. Ideally passengers would not notice either the beginning or end of the braking. An illustration in Roadcraft (p 111 in 2020 edition) shows a progressive increase in braking force to one-third of the braking distance, followed by a reduction in braking force over a longer distance. I generally take longer to get to peak braking force, and often make subtle changes in pressure to achieve a suitable speed where it is needed.
I have tried to very progressively build up the force too, but the issue I have is my mk8 fiesta is very 'on/off' switch with its brakes - initially there'll be nothing when you depress the pedal, but once the brakes kick in they firm up very quickly as you depress the pedal further. Have looked online and it seems to be a known issue with recent Fords. Don't get me wrong you can still brake smoothly, but can't build up the pressure as slowly as what I'd like/what I suspect you're alluding to.

Edited by Scott OSRS on Saturday 11th February 19:54