Gearchange video

[GreenV8S]

Yung Man said:

It's a bit like a DDC with only one D, IMO doing this involves reving the engine with the clutch pedal down instead of up, if you want to do that in your own car thats fine, you are the one paying the bills.

Good analogy, I think it's very much like that.

But why do you think that it is bad for the engine to rev it with the clutch down? What would you rather have him do instead?

Edited by GreenV8S on Saturday 1st September 17:43

[Santa Claws]

Makes no difference, revving an engine whilst the clutch pedal is down.

[Yung Man]

GreenV8S said:

Yung Man said:

It's a bit like a DDC with only one D, IMO doing this involves reving the engine with the clutch pedal down instead of up, if you want to do that in your own car thats fine, you are the one paying the bills.

Good analogy, I think it's very much like that (the only difference being that with DDC the timing of the rev change and the gear engagement is obviously critical - here it hardly matters).

Why do you think that it is bad for the engine to rev it with the clutch down?

Your not a school teacher are by any chance, why do I feel like I'm being backed into a corner.
Clutches on modern cars these days are reletively cheap and so whether they pack up at 100 150 or 200 thousand miles is neither here nor there, at the other end of the scale a formula one car could easily burn its clutch out doing one to many starts which I'm sure you will agree involves reving the engine with the clutch down, I know launching it off the line doesn't do it any good either but Reg's main concern is catching villains not worrying about a new clutch.
Because my boss (and the wife) wouldn't be best pleased if I went through clutches quicker than everybody else I think I'll stick with the DDC with H+T thrown in.

[R_U_LOCAL]

Yung Man said:

GreenV8S said:

Yung Man said:

It's a bit like a DDC with only one D, IMO doing this involves reving the engine with the clutch pedal down instead of up, if you want to do that in your own car thats fine, you are the one paying the bills.

Good analogy, I think it's very much like that (the only difference being that with DDC the timing of the rev change and the gear engagement is obviously critical - here it hardly matters).

Why do you think that it is bad for the engine to rev it with the clutch down?

Your not a school teacher are by any chance, why do I feel like I'm being backed into a corner.
Clutches on modern cars these days are reletively cheap and so whether they pack up at 100 150 or 200 thousand miles is neither here nor there, at the other end of the scale a formula one car could easily burn its clutch out doing one to many starts which I'm sure you will agree involves reving the engine with the clutch down, I know launching it off the line doesn't do it any good either but Reg's main concern is catching villains not worrying about a new clutch.
Because my boss (and the wife) wouldn't be best pleased if I went through clutches quicker than everybody else I think I'll stick with the DDC with H+T thrown in.

Stick with whatever you want, but my method has nothing to do with operational Police driving. It's the smoothest and most mechanically sympathetic method to change gear in a modern manual car.

DDC with H+T is all well and good, but the "blip" of the throttle is a far less accurate way of matching engine speed to road speed than my method, with far more scope for releasing the clutch at the wrong engine revs and therefore creating excessive wear on the clutch. As I've mentioned in several previous posts, revving the engine with the clutch depressed causes no wear on the friction plates whatsoever, and DDC by it's very nature involves operating the clutch twice as many times as with single-clutching, so there's more wear on the release bearing.

I've never once replaced a clutch in any car I've ever owned.

[Yung Man]

R_U_LOCAL said:

I've never once replaced a clutch in any car I've ever owned.

I don't think for one minute that if I was to ask you how many miles you had covered in your career you would exaggerate and use a particularly busy week as the norm but go on, how many miles have you covered?.

The reason I ask is because I have covered over 2 million and admittedly one clutch did go on me but It wasn't my vehicle, I haven't gone through any release bearings, so me DDC ing hasn't resulted in any extra bills.
My average yearly mileage is just short of 100,000 which equates to about 180 years average driving, I can't be doing much wrong.

[7db]

Yung Man said:

My average yearly mileage is just short of 100,000 which equates to about 180 years average driving, I can't be doing much wrong.

Must do a lot on the motorway (in one gear) to get that many...

[GreenV8S]

Yung Man said:

Your not a school teacher are by any chance, why do I feel like I'm being backed into a corner.

Clutches on modern cars these days are reletively cheap and so whether they pack up at 100 150 or 200 thousand miles is neither here nor there, at the other end of the scale a formula one car could easily burn its clutch out doing one to many starts which I'm sure you will agree involves reving the engine with the clutch down, I know launching it off the line doesn't do it any good either but Reg's main concern is catching villains not worrying about a new clutch.

Because my boss (and the wife) wouldn't be best pleased if I went through clutches quicker than everybody else I think I'll stick with the DDC with H+T thrown in.

No I'm not a school teacher.

I don't know why you feel like you're being backed into a corner. You've commented that the techniques R_U_LOCAL demonstrated show a lack of mechanical sympathy and I'm trying to understand why you said that. I don't think they show any lack of sympathy - quite the opposite in fact. But if you think that DDC and H+T are preferred techniques for normal road driving in a typical modern car and that revving an engine with the clutch disengaged causes significant wear and tear, we're probably starting from viewpoints that are a long way apart. It's a subject that interests me and I'd like to continue the discussion to see if we can reach a common understanding if you're interested, but don't feel any obligation to - I'm not trying to badger you into agreeing with me.

[vonhosen]

WilliBetz said:

vonhosen said:

I don't see that the references to what's written in Roadcraft circa 1960 compared to more recent versions provides much.

1960 didn't advocate overlaps IIRC, where as I think we would all mostly be of the opinion that overlaps on the grounds of safety are entirely appropriate.

Also 1960s training had very little input on essential attitude compared to today's training. Again I think we'd mostly agree that it's a hugely important input.

On the subject of overlaps and their applicability, you may be interested in the views of RoSPA's chief examiner. This article used to appear on their website, but seems to have been removed for some reason...

http://beehive.thisishull.co.uk/default.asp?WCI=Si...

Overlapping for progress isn't deemed acceptable where I work.
Overlapping as a matter of course certainly isn't taught.
Brake gear separation is taught & it is only acceptable to compromise the system (brake/gear separation) for safety, not speed. When the system is compromised in such a fashion it should be sold as part of a pre-planned approach, not as an attempt to justify post event.

When I was taught they didn't like overlapping at all. That had the potential to bring you in conflict with others where your application of the system may not meet with their reasonable expectations of what you would do.
Overlapping as I have described above (pre sold on the grounds of safety) being allowed was a step forward. It is in no way a negative addition, it doesn't give you carte blanche to overlap everywhere, it just allows you to do so in a few isolated cases where it's of benefit & typically these are very low speed situations.

The person referred to in the article (saying that brake gear separation is still taught) is now the Chief examiner of the IAM.

Edited by vonhosen on Saturday 1st September 20:29

[Yung Man]

GreenV8S said:

Yung Man said:

Your not a school teacher are by any chance, why do I feel like I'm being backed into a corner.

Clutches on modern cars these days are reletively cheap and so whether they pack up at 100 150 or 200 thousand miles is neither here nor there, at the other end of the scale a formula one car could easily burn its clutch out doing one to many starts which I'm sure you will agree involves reving the engine with the clutch down, I know launching it off the line doesn't do it any good either but Reg's main concern is catching villains not worrying about a new clutch.

Because my boss (and the wife) wouldn't be best pleased if I went through clutches quicker than everybody else I think I'll stick with the DDC with H+T thrown in.

No I'm not a school teacher.

I don't know why you feel like you're being backed into a corner. You've commented that the techniques R_U_LOCAL demonstrated show a lack of mechanical sympathy and I'm trying to understand why you said that. I don't think they show any lack of sympathy - quite the opposite in fact. But if you think that DDC and H+T are preferred techniques for normal road driving in a typical modern car and that revving an engine with the clutch disengaged causes significant wear and tear, we're probably starting from viewpoints that are a long way apart. It's a subject that interests me and I'd like to continue the discussion to see if we can reach a common understanding if you're interested, but don't feel any obligation to - I'm not trying to badger you into agreeing with me.

I'm not a mechanic by any stretch of the imagination and maybe if I changed my cars like the average motorist does every two and a half years wear and tear on the clutch wouldn'd be an issue with me, plus I might well be too stuck in my ways so I'll check up first just to make sure I'm not talking total boocks (I know you think I am anyway ).


I'll catch you later, have a good weekend.

[WilliBetz]

vonhosen said:

Overlapping for progress isn't deemed acceptable where I work.
Overlapping as a matter of course certainly isn't taught.
Brake gear separation is taught & it is only acceptable to compromise the system (brake/gear separation) for safety, not speed. When the system is compromised in such a fashion it should be sold as part of a pre-planned approach, not as an attempt to justify post event.

When I was taught they didn't like overlapping at all. That had the potential to bring you in conflict with others where your application of the system may not meet with their reasonable expectations of what you would do.
Overlapping as I have described above (pre sold on the grounds of safety) being allowed was a step forward. It is in no way a negative addition, it doesn't give you carte blanche to overlap everywhere, it just allows you to do so in a few isolated cases where it's of benefit & typically these are very low speed situations.

The person referred to in the article (saying that brake gear separation is still taught) is now the Chief examiner of the IAM.

Thanks, vonhosen. This seems to suggest that overlapping is now denigrated by both the IAM and RoSPA.

[7db]

Smells of dogma to me. I appreciate things need to be kept simple for the audience, but why not teach both and deploy one...

[vonhosen]

7db said:

Smells of dogma to me. I appreciate things need to be kept simple for the audience, but why not teach both and deploy one...

You don't have to do what the club I belong to does. You're not part of it, so you can do what you or any club you belong to dictates. There are reasons why the club I belong to do what they do & they aren't likely to be applicable to you.

Whatever the IAM & RoADA choose to do is again down to them. If you want to be a part of them then you'd only need to display to them that you can drive as per their rules when observed. You wouldn't have to all the time, what you do then would be your choice.

Edited by vonhosen on Saturday 1st September 22:59

[7db]

That's true in an isolationist way, but the other clubs that I don't belong to choose to take their driving direction from the club that you belong to so a little illumination might be useful and acknowledged or not, it has a role as custodian of the Grail...

But you're quite right - it's a secondary job to helping the people who are supposed to be catching the bad guys keeping it shiny side up.

Not sure how separation helps that. Does it?

[vonhosen]

7db said:

That's true in an isolationist way, but the other clubs that I don't belong to choose to take their driving direction from the club that you belong to so a little illumination might be useful and acknowledged or not, it has a role as custodian of the Grail...

But you're quite right - it's a secondary job to helping the people who are supposed to be catching the bad guys keeping it shiny side up.

Not sure how separation helps that. Does it?

With limited time & resources to train them, they haven't got time to master every technique. They have to be shown (& display that they can reliably & consistently produce to a competent standard) a way of driving that is fit for purpose & equips them to safely perform the task they are being asked to do.
One of the biggest benefits in separation is the safety buffer it creates in relation to speed on approach to hazards & as safety is a priority that is extremely beneficial. (Too high an approach speed being a significant contributory factor in collisions.)
You're not talking about training only the most gifted or even all enthusiasts, quite often you are trying to make a silk purse from a sows ear.

[7db]

Thanks Von. Keep turning out the purses as best you can.

[BertBert]

Interestingly, even though I have not become an Advanced Driver I have put a lot of effort into changing and improving my driving over the last 5 or so years including learning and practising non-overlapping.

I am currently learning to improve my track driving which is a different "club" in VH's parlance.

My Radical responds very well to being turned in before the end of braking (it stops understeer). I am having a bit of a time of it trying to:

a/ still have some braking left to do at the point of turning and
b/ get myself to turn whilst on the brakes.

Bert

[GreenV8S]

This is something that attracts a lot of attention among sprinters because it's a way to gain fractions of a second on every corner if you get it right. The most obvious way to show how much grip is being wasted is to produce a G-G plot of lateral versus longitudinal acceleration. With the really good drivers this will produce a fairly good 'D' shaped plot with maximum grip being used all the way through every corner. With drivers who don't trail brake the plot will be 'T' shaped with most braking done in a straight line. Everyone uses maximum grip on the way out of the corner, but the less experiences drivers don't use it on the way in.

I suppose the techniques will vary from person to person and I don't know whether this will work with you, but there are two techniques that I used to overcome the natural tendency not to fully commit on the way in. The first is to brake at the normal point but deliberately not brake as hard as possible and end up deliberately 'out-braking' myself. The response when I outbrake myself is already well practiced and is basically to stay on the brakes and take a very wide line into the corner and keep braking as deep as necessary to stay on the black stuff, so it's not too frightening and just needs a bit of gumption to put yourself in that situation. Being on the brakes and having extra braking in hand makes this much less traumatic though.

The second technique, having got used to the feel of the car turning in under braking and sorted out the timing of gear changes and the adjustment in racing line that comes with this, is to gradually brake later and harder to get into the same situation. I will get to the point where I expect to be able to make the corner without trail braking and then hang on for another half a second or a second before piling on the brakes. How long depends on how keen I am, and although I can do it I usually don't commit hard enough to use all available grip, I always keep some margin in hand. If I'm competing the margin will be very small though!

Edited by GreenV8S on Sunday 2nd September 15:37

[Yung Man]

Yung Man said:

GreenV8S said:

It's a subject that interests me and I'd like to continue the discussion to see if we can reach a common understanding if you're interested,

I'm not a mechanic by any stretch of the imagination and maybe if I changed my cars like the average motorist does every two and a half years wear and tear on the clutch wouldn'd be an issue with me, plus I might well be too stuck in my ways so I'll check up first just to make sure I'm not talking total boocks (I know you think I am anyway ).

This is a quote from an article I read,

"WHY DID THE CLUTCH FAIL?

Before you replace a clutch, it is a good idea to examine the old parts to see what might have caused them to fail. If you find an oil-soaked clutch, for example, do not even think about installing a new clutch until you have found and fixed the oil leak.

If the fingers on a diaphragm clutch show heavy wear, it may be because somebody did not install the release bearing correctly, the hydraulic system was not fully retracting, the release cable was sticking, misadjusted or had a defective self-adjuster, or the driver had the bad habit of riding the clutch.

If the fingers on a diaphragm clutch are worn unevenly, it means the clutch was distorted when it was installed because somebody did not tighten down the cover bolts evenly when it was bolted to the flywheel. The pressure plate will often show chatter marks on the side opposite the finger wear on the diaphragm."



It came from this page,

http://www.aa1car.com/library/2002/ic100237.htm

I'd like you to read the bit were they say, "or the driver had the bad habit of riding the clutch"

IMO riding the clutch and spending unnecessary time on the clutch whilst the engine is reving above tick over is similar, from this comment it leads one to believe the clutch will last longer if you us it as little as possible.
You might say DDC is using it unnecessarily but the revs are low when you dip the clutch and it's in nuetral when you blip it.

[Santa Claws]

Yung Man said:

IMO riding the clutch and spending unnecessary time on the clutch whilst the engine is reving above tick over is similar, from this comment it leads one to believe the clutch will last longer if you us it as little as possible.
You might say DDC is using it unnecessarily but the revs are low when you dip the clutch and it's in nuetral when you blip it.

Spending time on the clutch i.e. pedal is all the way to the floor (open clutch); or spending time on the clutch i.e. holding the clutch on the biting point with a bit of revs? You have to be clear here.

The latter is riding the clutch and causes wear on the clutch disc (as your little link points out). The former, however, is NOT riding the clutch and causes no wear to the clutch disc itself. It can, however, affect the release bearings. However, that is rare.

/edit: Just to add, with the clutch disengaged (i.e. pedal all the way to the floor, just to clarify!!) you can rev the engine all you like, and it will NOT cause wear to the clutch. When you are rev matching either by sustaining revs or blipping the throttle, you try to get the revs exactly right for the lower gear before you feed the clutch out. If the revs are matched up, then no wear occures on the clutch when it is re-engages.

Edited by Santa Claws on Sunday 2nd September 22:07

[GreenV8S]

Yung Man said:

I'd like you to read the bit were they say, "or the driver had the bad habit of riding the clutch"

I agree riding the clutch is a bad habit and will cause increased wear on the clutch release bearing. However, holding the clutch down for a couple of seconds during a gear change is not 'riding the clutch' and won't cause any significant wear. You may not feel like taking my word for it, but I assure you that the technique R_U_LOCAL showed us doesn't cause any undue wear; on the contrary it is just about the least damaging gear change technique that is possible.

Edited by GreenV8S on Sunday 2nd September 22:39