Is a disengaged clutch the same as being in neutral?

Jonathan_Powell

The same in regards to wear and tear. On a hill, I hardly use the handbrake and keep the car in gear with both the foot brake and clutch being all the way down. I have always been told that keeping a car on a hill by using the clutch is very bad but if you have the clutch all the way down does that save it? 

daveyjp

It is better mechanically to use the handbrake and select neutral, it removes stress on the thrust bearings in the clutch, and releases pressure in the clutch hydraulic system.

molerat

As above and even with the clutch fully down there will still be some friction wear between the spinning components. Plus jumping from footbrake to throttle can allow you to rollback, another reason why it is not recommended, unless you have hill start assist.  An electric handbrake makes it a no brainer to use the handbrake every time though.

AdrianC

No, it isn't the same.

There are four parts to a clutch.
There's the driven plate (part of the flywheel, fixed to the engine), and the pressure plate (spring-loaded). Between them, there's the friction plate (which is what wears out). When you put your foot on the clutch, the release bearing is pushed against the pressure plate, pushing against the spring pressure and allowing the friction plate to rotate separately from the driven and pressure plates.

While it's rotating separately, there's some friction, and that's what wears it. Obviously, as you take your foot on or off the pedal, there's more friction as it's only partially separated.
Biting point is when the friction plate is just about gripping enough to overcome all the other forces holding the car stationary - so that's also the point at which there's most wear on the friction plate.

So all the time your foot is on the clutch pedal, there's pressure on the release bearing, pushing hard against the spring pressure while rotating 800 times a minute at engine idle.

The clutch's job is to disengage drive temporarily between the engine and gearbox. If the gearbox is in neutral, you can let your foot off the clutch, letting all the forces go from the release bearing and stopping the friction plate wearing.

https://www.youtube.com/watch?v=6DL0j0eKD8Y

molerat

One of those annoying people who sit at traffic lights at night in gear with foot on clutch and brake. I remember asking someone what they thought of the stop-start system when at traffic lights, they said didn't know as it only worked when they parked the car !  All the time your foot is on the clutch pedal it is wearing the friction plate and thrust bearings.

John_

Jonathan_Powell said:

The same in regards to wear and tear. On a hill, I hardly use the handbrake and keep the car in gear with both the foot brake and clutch being all the way down. I have always been told that keeping a car on a hill by using the clutch is very bad but if you have the clutch all the way down does that save it? 

You are wearing the clutch thrust bearing, and are also risking dazzling the driver behind with your brake lights, and risking jumping into the car in front of knocked from behind.

Better to put the car in neutral and apply the hand brake.

nottsphil

AdrianC said:

https://www.youtube.com/watch?v=6DL0j0eKD8Y

I really didn't get that. Why are the cogs on the chrome disk going in the opposite direction? At first I thought it must be the 'wagon wheel' illusion where the spoke speed matches the frames per second, but surely that wouldn't apply to a cartoon? 

AdrianC

nottsphil said:

AdrianC said:

https://www.youtube.com/watch?v=6DL0j0eKD8Y

I really didn't get that. Why are the cogs on the chrome disk going in the opposite direction? At first I thought it must be the 'wagon wheel' illusion where the spoke speed matches the frames per second, but surely that wouldn't apply to a cartoon? 

The starter ring gear on the flywheel. They're the teeth the starter motor engages with.

They aren't going the opposite way. Or, rather, they won't be in real life. There's no reason why an animation being drawn/CGI rather than filmed would change the optical illusion.

nottsphil

A

AdrianC said:

nottsphil said:

AdrianC said:

https://www.youtube.com/watch?v=6DL0j0eKD8Y

I really didn't get that. Why are the cogs on the chrome disk going in the opposite direction? At first I thought it must be the 'wagon wheel' illusion where the spoke speed matches the frames per second, but surely that wouldn't apply to a cartoon? 

The starter ring gear on the flywheel. They're the teeth the starter motor engages with.

They aren't going the opposite way. Or, rather, they won't be in real life. There's no reason why an animation being drawn/CGI rather than filmed would change the optical illusion.

CGI maybe not, but drawn cartoons were traditionally copied then altered slightly to align with the next frame. I'm sure it would be obvious to the artist if the subsequent frame appeared to show the cog moving in the opposite direction. 

Biggus_Dickus

nottsphil said:

A

AdrianC said:

nottsphil said:

AdrianC said:

https://www.youtube.com/watch?v=6DL0j0eKD8Y

I really didn't get that. Why are the cogs on the chrome disk going in the opposite direction? At first I thought it must be the 'wagon wheel' illusion where the spoke speed matches the frames per second, but surely that wouldn't apply to a cartoon? 

The starter ring gear on the flywheel. They're the teeth the starter motor engages with.

They aren't going the opposite way. Or, rather, they won't be in real life. There's no reason why an animation being drawn/CGI rather than filmed would change the optical illusion.

CGI maybe not, but drawn cartoons were traditionally copied then altered slightly to align with the next frame. I'm sure it would be obvious to the artist if the subsequent frame appeared to show the cog moving in the opposite direction. 

They should have made it using Wallace & Gromit style ‘Clay-mation’,...there’s no ambiguity with that.

Scrapit

Jonathan_Powell said:

The same in regards to wear and tear. On a hill, I hardly use the handbrake and keep the car in gear with both the foot brake and clutch being all the way down. I have always been told that keeping a car on a hill by using the clutch is very bad but if you have the clutch all the way down does that save it? 

Regardless of if they are the same, you dont have enough feet. Foot 1 depresses the clutch, foot 2 holds down the brakes which holds the vehicle on the hill cos the hand brake isn't being used. When the way is clear to proceed you can't rev the car and reach the clutch biting point whilst holding position on the hill using the footbrake. Use the hand brake to hold the vehicle and use your left foot to adjust clutch, right foot car work the stop and go peddles as required. Or get an auto.