Turning in smooth and early
Discussion
Big Fat F'er said:
willibetz said:
....it seems suspect on lines and even worse when it comes to physics.
?
BFF
The article advocates adopting a wide line for visibility, without discussing when to adapt that line for stability. Therefore, it seems to suggest driving round the outside of any bend. Indeed, the lack of a defined "apex" in the advocated line is reinforced by the diagrams.
The suggested adoption of a wide line (over the centre line) into left hand bends is suspect (perhaps von could offer a contemporary police view), especially paired with the advice (elsewhere in the article) that you should practise at low speeds. The technique (which may or may not be regarded as current best practice) depends on you carrying enough speed to return to your side of the road before an oncoming car is aware of you positioning strongly. At low speed, all you'll get is an earlier view of the car that hits you, or steers off the road for fear of hitting you.
As far as the physics goes, the use of the term centrifugal force in the article is incorrect. The cornering car has a centripetal force acting upon it (generated by the tyres) but there is no centrifugal or outward force acting on the car. Newton's laws apply.
WilliBetz
Edited by willibetz on Sunday 19th November 15:54
willibetz said:
The article advocates adopting a wide line for visibility, without discussing when to adapt that line for stability. Therefore, it seems to suggest driving round the outside of any bend.
Not really. It's suggesting that you take the wider view only when you can see that it is safe to take it. This gives a clearer view and stabilises the car (a stright line is a stable line, etc). You do not go out to get the view, and the article doesn't tell you to do that. It tells you to take close to the edge on the RH, and keep on your side of the road on the LH. Unless you can already see that there are no vehicles, in which you can go wider if appropriate.
willibetz said:
The suggested adoption of a wide line (over the centre line) into left hand bends is suspect
No it' s not, when it's done appropriately. This applies to both Civilian and Police driving. However, your comments definitely emphasise the thing we covered earlier, which is that the printed word is not meant to be everything. Training should come with it.
willibetz said:
...the advice (elsewhere in the article) that you should practise at low speeds.
That particular bit is specifically relating to coming off line, but it does apply to any cornering technique. Don't you wish that more would take the time and trouble to practice at the right speed.
willibetz said:
The technique (which may or may not be regarded as current best practice) depends on you carrying enough speed to return to your side of the road before an oncoming car is aware of you positioning strongly. At low speed, all you'll get is an earlier view of the car that hits you, or steers off the road for fear of hitting you.
If you can't see that there is a vehicle, you shouldn't be out there. You DON'T go out (offside) to get a view. The article (and all personal Advanced training) emphasises that. What the article does do is state quite clearly the 4 key things about cornering, which is detailed on everty single training course going. You need to be in the correct position, speed, gear, and be able to stop on your side of the road in the distance you can see to be clear.
willibetz said:
As far as the physics goes, the use of the term centrifugal force in the article is incorrect. The cornering car has a centripetal force acting upon it (generated by the tyres) but there is no centrifugal or outward force acting on the car. Newton's laws apply.
Correct, but it is an oft repeated mistake.
Don't forget, the article is describing Civilian driving, within the law. As such , it is only saying the same as all the rest. It is there to give safety top priority. Then information. Which is why the Advanced drivers that recommend always taking the position near the crown on a LH (to get the view) are wrong. You don't always do it.
The article doesn't suggest what you appear to have read into it. If more people cornered like that there may be less near misses and fewer head ons.
BFF
BFF,
Having read the article again, I can accept some of your comments. In particular, I see that it does attempt to give clear guidance as to when offsiding is sensible.
I would comment though that I have sat with some very highly regarded instructors who position wide on the entry to nearside bends with less than full visibility, knowing that their pace is sufficient to return seamlessly to their lane (and still be able to stop) should the situation require. I understand that this has been a bit of a hot topic for police drivers under instruction, and it would be interesting to get Vonhosen's expert view on current thinking.
But, even after rereading, it still seems to me that it the article advocates (both in writing and pictures) driving around the outside of bends. Which ain't right.
WilliBetz
Having read the article again, I can accept some of your comments. In particular, I see that it does attempt to give clear guidance as to when offsiding is sensible.
I would comment though that I have sat with some very highly regarded instructors who position wide on the entry to nearside bends with less than full visibility, knowing that their pace is sufficient to return seamlessly to their lane (and still be able to stop) should the situation require. I understand that this has been a bit of a hot topic for police drivers under instruction, and it would be interesting to get Vonhosen's expert view on current thinking.
But, even after rereading, it still seems to me that it the article advocates (both in writing and pictures) driving around the outside of bends. Which ain't right.
WilliBetz
willibetz said:
BFF,
Having read the article again, I can accept some of your comments. In particular, I see that it does attempt to give clear guidance as to when offsiding is sensible.
I would comment though that I have sat with some very highly regarded instructors who position wide on the entry to nearside bends with less than full visibility, knowing that their pace is sufficient to return seamlessly to their lane (and still be able to stop) should the situation require. I understand that this has been a bit of a hot topic for police drivers under instruction, and it would be interesting to get Vonhosen's expert view on current thinking.
But, even after rereading, it still seems to me that it the article advocates (both in writing and pictures) driving around the outside of bends. Which ain't right.
WilliBetz
Having read the article again, I can accept some of your comments. In particular, I see that it does attempt to give clear guidance as to when offsiding is sensible.
I would comment though that I have sat with some very highly regarded instructors who position wide on the entry to nearside bends with less than full visibility, knowing that their pace is sufficient to return seamlessly to their lane (and still be able to stop) should the situation require. I understand that this has been a bit of a hot topic for police drivers under instruction, and it would be interesting to get Vonhosen's expert view on current thinking.
But, even after rereading, it still seems to me that it the article advocates (both in writing and pictures) driving around the outside of bends. Which ain't right.
WilliBetz
My view
There is a difference of opinion on this within a lot of schools. Some will advocate using the whole road where safe, others not.
If you are going to do it, it is very important that you do it right.
Very few who come to me do initially.
They go about it completely arse about face, positioning overtly where there is greater risk for little benefit (they perceive there is benefit, but when they actually look at it in detail they admit there isn't) & then not using advantage where there is greater benefit for little risk (usually here they haven't even seen the opportunity or considered it, but at least that doesn't compromise safety).
This positioning is definitely one thing where a little knowledge can be a very bad thing.
As I said above, you can only use the full road to Reduce the forces acting on the vehicle where you have satisfied those above it in the list. (i.e. that you have the Information (vision) to see that it is Safe.)
It's not enough to think that it is, it *must* be.
It's not just about being able to stop back on your side of the road, it's also about the effect your unexpected positioning could have on anyone as yet unseen. You shouldn't be taking such positions at all, if the road surface is hidden from you or where others could be hidden.
For most at normal road speeds, there is little or no benefit from such positioning though.
Edited by vonhosen on Sunday 19th November 20:09
willibetz said:
the article advocates (both in writing and pictures) driving around the outside of bends. Which ain't right.
Willibetz - why?
Bearing in mind who the article is aimed at, and what it is trying to achieve, why do you think the advice is wrong?
Is it that you disagree that the positioning will give the benefits as defined, or is it that you don't think the benefits are worthwhile.
BFF
Once again, dashing out, so R&O. Speak later.
Edited by Big Fat F'er on Sunday 19th November 20:03
Big Fat F'er said:
willibetz said:
The article advocates adopting a wide line for visibility, without discussing when to adapt that line for stability. Therefore, it seems to suggest driving round the outside of any bend.
Not really. It's suggesting that you take the wider view only when you can see that it is safe to take it. This gives a clearer view and stabilises the car (a stright line is a stable line, etc). You do not go out to get the view, and the article doesn't tell you to do that. It tells you to take close to the edge on the RH, and keep on your side of the road on the LH. Unless you can already see that there are no vehicles, in which you can go wider if appropriate.
If it stops the 95% of numpties who take a right-hander with two wheels over the centre line, I'm all for it.
<snip>
Big Fat F'er said:
willibetz said:
As far as the physics goes, the use of the term centrifugal force in the article is incorrect. The cornering car has a centripetal force acting upon it (generated by the tyres) but there is no centrifugal or outward force acting on the car. Newton's laws apply.
Correct, but it is an oft repeated mistake.
Nope. In the reference frame of the moving vehicle, the force is very real. In the reference frame of the road, it may well be inertia versus centripetal force, but in the accelerating reference frame of the car, it's centrifugal force that's acting.
Big Fat F'er said:
willibetz said:
the article advocates (both in writing and pictures) driving around the outside of bends. Which ain't right.
Willibetz - why?
Bearing in mind who the article is aimed at, and what it is trying to achieve, why do you think the advice is wrong?
I assume that the article is trying to set out the thinking behind, and course of, an ideal cornering line. I assume that it is aimed at people interested in learning said reasoning and line. If those assumptions are correct, I think it's deficient.
If somebody adopted the line described / drawn, and asked me for my opinion, I'd suggest taking an apex once safety and view were assured. Driving around the outside of the bend prolongs the bend, does nothing to reduce lateral forces on the car at the end of the bend, and means you can't accelerate as much or as soon.
Major Bloodnok said:
willibetz said:
As far as the physics goes, the use of the term centrifugal force in the article is incorrect. The cornering car has a centripetal force acting upon it (generated by the tyres) but there is no centrifugal or outward force acting on the car. Newton's laws apply.
Nope. In the reference frame of the moving vehicle, the force is very real. In the reference frame of the road, it may well be inertia versus centripetal force, but in the accelerating reference frame of the car, it's centrifugal force that's acting.
Frames of reference are important. And the important one here is the article, which refers to conkers on strings and keeping "centrifugal force acting upon the car to a minimum". In this context the term centrifugal force is misused. The force acting on the conker or car is centripetal and causes the object to "accelerate", which in this context means to describe a curved trajectory rather than necessarily alter its speed. There is no outward force acting on conker, the car or its occupants.
Perhaps it's a minor point. But, given that it's easy to describe a line and its benefits without recourse to scientific terminology (as Vonhosen has), it's a shame that the article's author deemed it necessary to introduce specific terms and use them incorrectly.
WilliBetz
edited for clarity
Edited by willibetz on Monday 20th November 12:10
Major Bloodnok said:
If it stops the 95% of numpties who take a right-hander with two wheels over the centre line, I'm all for it.
Major - Absolutely. in fact, one of the observation links we now go for is "travelling uphill into a Left hander, so cars will be towards over the centre line". Cars go over the centre on a downhill right hander almost 100%.
willibetz said:
Major Bloodnok said:
willibetz said:
As far as the physics goes, the use of the term centrifugal force in the article is incorrect. The cornering car has a centripetal force acting upon it (generated by the tyres) but there is no centrifugal or outward force acting on the car. Newton's laws apply.
Nope. In the reference frame of the moving vehicle, the force is very real. In the reference frame of the road, it may well be inertia versus centripetal force, but in the accelerating reference frame of the car, it's centrifugal force that's acting.
Frames of reference are important. And the important one here is the article, which refers to conkers on strings and keeping "centrifugal force acting upon the car to a minimum". In this context the term centrifugal force is misused. The force acting on the conker or car is centripetal and causes the object to "accelerate", which in this context means to describe a curved trajectory rather than necessarily alter its speed. There is no outward force acting on conker, the car or its occupants.
Perhaps it's a minor point. But, given that it's easy to describe a line and its benefits without recourse to scientific terminology (as Vonhosen has), it's a shame that the article's author deemed it necessary to introduce specific terms and use them incorrectly.
WilliBetz
edited for clarity
Edited by willibetz on Monday 20th November 12:10
Oh, I agree that using scientific terminology (especially when you or your audience are not really sure what the terms mean) can be counter-productive. I was just pointing out that the statement "there's no such thing as centrifugal force" is not entirely correct.
Big Fat F'er said:
Major - Absolutely. in fact, one of the observation links we now go for is "travelling uphill into a Left hander, so cars will be towards over the centre line". Cars go over the centre on a downhill right hander almost 100%.
In my experience, the "hill" is an unnecessary addition. Cheshire is not known for the amount of up and down it contains, but I can guarantee that the majority of people coming round a right-hander will be in a position of real danger. But, yeah, hills do push it up to 100%...
WilliBetz said:
A couple of very quick thoughts...
A tendency to turn in early is frequently indicative of a driver who lacks confidence in their assessment of entry speed or the car's ability to grip. That's not a place you want to be.
WilliBetz
A tendency to turn in early is frequently indicative of a driver who lacks confidence in their assessment of entry speed or the car's ability to grip. That's not a place you want to be.
WilliBetz
I realise this will me put me firmly in the camp of those who cannot drive, but as I read this board to learn, I'm prepared for helpful criticism.
Even on sighted corner you will never be sure of the exact grip level, there may be oil, leaves, etc, and unlike a track where lap after lap you learn the conditions, it could differ dramatically from the last time you took the corner. By turning in early on the road, can you not gain feedback, which then allows you to adjust the attitude of the car accordingly?
Of course smoothness is always the key, and taking two bites at a corner is a bad thing, but in theory at least (I'm not sure if I turn in early or not, I will have to see next time I drive on suitable roads) I can't really see the down side.
It's hard to comment on a description, Sato.
All I can suggest is giving consideration to some possible outcomes:
- if you turn in early and the car grips, then what line will you follow? Will you have to correct that line? What if good grip is afforded at the point that you turn in, but then lost mid bend?
- if you turn in early and the car doesn't grip, what will you do about it? Will you have reduced your chances of slowing the car, as brakes don't work as well when steering is applied (demonstrated at http://blog.cardomain.com/blog/2006/1 )? Is this approach a good way to judge an appropriate speed for the corner?
All said in the context of a road drive, as the approach to learning a new car and its reactions on circuit might differ.
WilliBetz
All I can suggest is giving consideration to some possible outcomes:
- if you turn in early and the car grips, then what line will you follow? Will you have to correct that line? What if good grip is afforded at the point that you turn in, but then lost mid bend?
- if you turn in early and the car doesn't grip, what will you do about it? Will you have reduced your chances of slowing the car, as brakes don't work as well when steering is applied (demonstrated at http://blog.cardomain.com/blog/2006/1 )? Is this approach a good way to judge an appropriate speed for the corner?
All said in the context of a road drive, as the approach to learning a new car and its reactions on circuit might differ.
WilliBetz
Edited by willibetz on Wednesday 22 November 10:58
willibetz said:
words
Now you have elaborated, it does make more sense.
I think where I was coming from was that although we would strive neither to turn in too early or late, turning in early would give you more options, but as you pointed out it would take a high level of skill to 'save' a car in such a scenario.
As I said previously I'm not even sure whether I do turn in early or not, but half the skill with this (slightly more) advanced driving stuff is being both able to recognise what you do and don't do, and being able to communicate it.
I think that as Von said a while back on this thread, the way to tell whether you have taken the right course/speed through a corner is to decide whether you were safe, had sufficient visibility, and have minimised the forces on the vehicle. Minimising the forces is something that requires thought and practice, but on the road it will probably not be the main factor that determines your course and speed through the corner.
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