Changing gear on level Crossing?

[PhilAsia]

Lincsls1 said:

What a load of bks!
Given that many of these crossings are actually rather bumpy, the best thing to do is slow down before it, keep a firm grip on the wheel with both hands and do any (manual) gear changes either before or after.

Disengaging the drivetrain is the part of the gearchange that I would (possibly - dependent on circumstances) be doing.

Edit: Ah! Just seen Jimbo's post. I think it still applies where circumstances warrant.

[911hope]

PhilAsia said:

Lincsls1 said:

What a load of bks!
Given that many of these crossings are actually rather bumpy, the best thing to do is slow down before it, keep a firm grip on the wheel with both hands and do any (manual) gear changes either before or after.

Disengaging the drivetrain is the part of the gearchange that I would (possibly - dependent on circumstances) be doing.

Edit: Ah! Just seen Jimbo's post. I think it still applies where circumstances warrant.

And...the same....for all the other types of bumps in the road?

[PhilAsia]

911hope said:

PhilAsia said:

Lincsls1 said:

What a load of bks!
Given that many of these crossings are actually rather bumpy, the best thing to do is slow down before it, keep a firm grip on the wheel with both hands and do any (manual) gear changes either before or after.

Disengaging the drivetrain is the part of the gearchange that I would (possibly - dependent on circumstances) be doing.

Edit: Ah! Just seen Jimbo's post. I think it still applies where circumstances warrant.

And...the same....for all the other types of bumps in the road?

Dependent on the bumps, yes. Purely to protect the drivetrain.

[911hope]

PhilAsia said:

Dependent on the bumps, yes. Purely to protect the drivetrain.

That will probably double the number of clutch activations on any journey where I live. Leading to premature wear.

Obviously no-one would do this and it isn't necessary or sensible.

[PhilAsia]

911hope said:

PhilAsia said:

Dependent on the bumps, yes. Purely to protect the drivetrain.

That will probably double the number of clutch activations on any journey where I live. Leading to premature wear.

Obviously no-one would do this and it isn't necessary or sensible.

Depends on your clutchwork. I double-declutch all the time and have never had to change a clutch, not even in my tuition vehicles.

[911hope]

PhilAsia said:

Depends on your clutchwork. I double-declutch all the time and have never had to change a clutch, not even in my tuition vehicles.

Not hard to drive with mechanical sympathy, without going to such lengths. That's why the vast majority of people never need to change a clutch.

Anyway please explain what is being gained by double declutching, and how does it offset the additional (double) clutch activations in terms of wear.

[PhilAsia]

911hope said:

Not hard to drive with mechanical sympathy, without going to such lengths. That's why the vast majority of people never need to change a clutch.

Anyway please explain what is being gained by double declutching, and how does it offset the additional (double) clutch activations in terms of wear.

You stated that "it is not hard to drive with mechanical sympathy", then ask me to "explain what is bein gained by double declutching". The same driver, with the same mechanical sympathy will see less wear when double declutching over the lifetime of the car - but I thought you knew that.

[911hope]

PhilAsia said:

You stated that "it is not hard to drive with mechanical sympathy", then ask me to "explain what is bein gained by double declutching". The same driver, with the same mechanical sympathy will see less wear when double declutching over the lifetime of the car - but I thought you knew that.

That's not the explanation I was hoping for, where I could learn the specific mechanism for saving wear, and on which components and by how much.

Much to explain.

[PhilAsia]

911hope said:

PhilAsia said:

You stated that "it is not hard to drive with mechanical sympathy", then ask me to "explain what is bein gained by double declutching". The same driver, with the same mechanical sympathy will see less wear when double declutching over the lifetime of the car - but I thought you knew that.

That's not the explanation I was hoping for, where I could learn the specific mechanism for saving wear, and on which components and by how much.

Much to explain.

No, not much to explain. You yourself stated that "it is not hard to drive with mechanical sympathy". Either you know and it is easy for you grasp and implement, or it is not, which is it?

[fttm]

Some serious OCD and paranoia going on in here , my first visit but the thread title got me , jeez . Re double de-clutching, absolutely no need with modern synchros .Crash box on an 18 speed needs it for the driving test , afterwards it’s clutch less changes all day long . Sorry to interrupt, as you were . Lol

[911hope]

PhilAsia said:

No, not much to explain. You yourself stated that "it is not hard to drive with mechanical sympathy". Either you know and it is easy for you grasp and implement, or it is not, which is it?

I now grasp that you know less about it than I had hoped.

You could have told me that it is all about balancing the speed of both ends of the gearbox, prior to engaging the next gear and resuming drive. This would have been easy to look up, but then you would have also found that this task is already done by the synchro system, so is a redundant technique (only true for about 50 years). So all that is achieved is more clutch cycles.

[PhilAsia]

911hope said:

PhilAsia said:

No, not much to explain. You yourself stated that "it is not hard to drive with mechanical sympathy". Either you know and it is easy for you grasp and implement, or it is not, which is it?

I now grasp that you know less about it than I had hoped.

You could have told me that it is all about balancing the speed of both ends of the gearbox, prior to engaging the next gear and resuming drive. This would have been easy to look up, but then you would have also found that this task is already done by the synchro system, so is a redundant technique (only true for about 50 years). So all that is achieved is more clutch cycles.

You stated that "mechanical sympathy is easy."

1) If it is easy, why was synchromesh introduced?

2) Why do manufacturers go to the bother of "auto-blip" systems - systems that reduce human wear and tear due to more proficient application of the techniques you deem to be "easy"?

I have another question for you after you have answered the above. Re, why neutral/clutch up is so important...

I have spent a large part of my life guiding drivers to become better at their craft. For some it is easy, for the majority it is not. If you fall into the former, great! Di Grassis Tyson being able to understand the Higg's bosun does not make it any easier for me, but I'm sure you have other thoughts.

[911hope]

PhilAsia said:

You stated that "mechanical sympathy is easy."

1) If it is easy, why was synchromesh introduced?

2) Why do manufacturers go to the bother of "auto-blip" systems - systems that reduce human wear and tear due to more proficient application of the techniques you deem to be "easy"?

I have another question for you after you have answered the above. Re, why neutral/clutch up is so important...

I have spent a large part of my life guiding drivers to become better at their craft. For some it is easy, for the majority it is not. If you fall into the former, great! Di Grassis Tyson being able to understand the Higg's bosun does not make it any easier for me, but I'm sure you have other thoughts.

Again no explanation. Just questions.

On your neural/clutch question, are we talking stationary or mid gear change?

Here are some answers, for you.

1. Since synchromesh does now exist (for about 50 years, simple rev matching is all that is required to be kind to the drive train.
Synchromesh makes double declutching redundant, so why do it?

If there is something I am missing, in terms of DDC benefits, which can be explained, I would be glad to learn.

2. Autoblip is simply a system to substitute for rev matching (on downshifts). As to why..Obviously since it is a control system, it be more reliable than a person. Also it sounds sporty and is a Feature to differentiate their product.

As well as increasing mechanical sympathy, to removes drive train braking impulse while breaking and possibly locking up on drive wheels. More likely in rear wheel drive car.

Surprise that someone training drivers cannot or will not explain these things.

What do you say, when a pupil asks?

Anything you disagree with?
Anything else we can discuss

Edited by 911hope on Tuesday 17th October 14:00

[PhilAsia]

911hope said:

PhilAsia said:

You stated that "mechanical sympathy is easy."

1) If it is easy, why was synchromesh introduced?

2) Why do manufacturers go to the bother of "auto-blip" systems - systems that reduce human wear and tear due to more proficient application of the techniques you deem to be "easy"?

I have another question for you after you have answered the above. Re, why neutral/clutch up is so important...

I have spent a large part of my life guiding drivers to become better at their craft. For some it is easy, for the majority it is not. If you fall into the former, great! Di Grassis Tyson being able to understand the Higg's bosun does not make it any easier for me, but I'm sure you have other thoughts.

Again no explanation. Just questions.

Yes. You stated it was easy, not me.

911hope said:

On your neutral/clutch question, are we talking stationary or mid gear change?

Neutral phase of DDC (with the clutch up), at the point the rev match is made.

911hope said:

1. Since synchromesh does now exist (for about 50 years, simple rev matching is all that is required to be kind to the drive train.

No, simple rev matching when the clutch is not up can cause more wear. I also asked "why was synchromesh introduced if the techniques for limiting wear and tear are so "easy" - your claim not mine.

911hope said:

Synchromesh makes double declutching redundant, so why do it?

Because there is the minimum of wear and tear on the drivetrain when done correctly.

911hope said:

2. Autoblip is simply a system to substitute for rev matching. As to why..Obviously since it is a control system, so it be more reliable than a person. Also it sounds sporty and is a Feature to differentiate their product.

But it is not necessary according to you. Why do the manufacturers program the feature to be more proficient than their human counterpart. Surely human rev-matching must be difficult to better if it is so easy.?

911hope said:

Surprise that someone training drivers cannot or will not explain these things.

Why would I explain it to you? You said it was easy. You understand some of the reason why it is done, but do not appear to be clear on the wear and tear side. The differences are there...

[911hope]

PhilAsia said:

Why would I explain it to you? You said it was easy. You understand some of the reason why it is done, but do not appear to be clear on the wear and tear side. The differences are there...

Ok..

Given that synchromesh exists which aligns speed of bothe ends of gearbox, and rev matching (either auto or driver) exists, which aligns engine and gearbox rotation, how exactly does using DDC reduce wear further? I cannot think of a mechanism that would explain it.

If you actually know, please be specific about the system component impacted and mechanism involved.

Further evasion should be considered as confirmation that you just believe it so and have never thought it through.

If you can explain the benefit, I would be delighted to learn. All I have done is think the problem through using a basic knowledge of the mechanics, so would benefit from superior knowledge, if you can provide it.

[Pica-Pica]

fttm said:

Some serious OCD and paranoia going on in here , my first visit but the thread title got me , jeez . Re double de-clutching, absolutely no need with modern synchros .Crash box on an 18 speed needs it for the driving test , afterwards it’s clutch less changes all day long . Sorry to interrupt, as you were . Lol

Agree. Either change as normal, or practise to achieve clutchless gear changes. None of this DDC ‘halfway house’ malarkey.

[Somewhatfoolish]

fttm said:

Some serious OCD and paranoia going on in here

Is this your first visit to an advanced driving forum? That's exactly why we like it!

[PhilAsia]

911hope said:

PhilAsia said:

Why would I explain it to you? You said it was easy. You understand some of the reason why it is done, but do not appear to be clear on the wear and tear side. The differences are there...

If you can explain the benefit, I would be delighted to learn. All I have done is think the problem through using a basic knowledge of the mechanics, so would benefit from superior knowledge, if you can provide it.

I have noticed you are quite scathing of others that pose questions on the AD forum... stating that their questions are not "advanced", but are "basic" as far as you are concerned.

You stated that mechanical sympathy is "easy", I disagree.

DDC has been covered many times in this forum and your questions have all been answered to a satisfactory level of enquiry. Go and do the heavy lifting for yourself - the discussions will furnish you with the answers that you require, as they are far better written and with a far better insight from an engineering perspective than I would ever profess to have.

Off you pop...

[Haltamer]

Very good idea - If you fudge the change horribly, everyone will blame the bumpy crossing

[911hope]

PhilAsia said:

I have noticed you are quite scathing of others that pose questions on the AD forum... stating that their questions are not "advanced", but are "basic" as far as you are concerned.

You stated that mechanical sympathy is "easy", I disagree.

DDC has been covered many times in this forum and your questions have all been answered to a satisfactory level of enquiry. Go and do the heavy lifting for yourself - the discussions will furnish you with the answers that you require, as they are far better written and with a far better insight from an engineering perspective than I would ever profess to have.

Off you pop...

I sometimes pose questions to those that profess expertise. Often the answers are not forthcoming, as is the case here.