thirdcrank wrote:Surely, nobody is suggesting that riding the clutch is good driving? Apart from anything else, there's a real risk of the vehicle running backwards, just as happened here.
I'm not suggesting that riding the clutch is good driving. But using the engine to hold the car on a hill is an alternative to rolling backwards in the event that a handbrake cannot be used.
I don't recommend practicing where rolling backwards is likely to cause problems.
The risk of rolling backwards is quite small for someone who has practiced the technique. Certainly much lower than just trying to get the foot as fast as possible from the brake to the accelerator.
“In some ways, it is easier to be a dissident, for then one is without responsibility.” ― Nelson Mandela, Long Walk to Freedom
I can see two scenarios although there may be others.
One is that the hill is so steep that the handbrake can't hold it. In which case, I'm unclear how a driver might get to the point of balancing the clutch in the first place. The other is that the handbrake isn't working properly, if at all. Then, it's illegal to drive the vehicle.
Somebody above mentioned being required to do this in the driving test and IIRC it is (or was) called clutch control and the point is that it may, on occasions, be appropriate not to set the handbrake very briefly when pausing at a junction. Otherwise, it's a bit like central heating controls: the billpayer is always much more cautious than everybody else. Fleet vehicles can suffer from the treatment because the drivers couldn't care less about damaging the clutch.
The actual scenario was a car with an automatic handbrake. The driver can not keep the handbrake applied, the car automatically releases it and it does so before you can get the clutch to the bite point with your other foot on the accelerator.
meic wrote:The actual scenario was a car with an automatic handbrake. The driver can not keep the handbrake applied, the car automatically releases it and it does so before you can get the clutch to the bite point with your other foot on the accelerator.
It would be illegal to use such a vehicle per TC
Entertainer, juvenile, curmudgeon, PoB, 30120 Cycling-of course, but it is far better on a Gillott We love safety cameras, we hate bullies
meic wrote:The actual scenario was a car with an automatic handbrake. The driver can not keep the handbrake applied, the car automatically releases it and it does so before you can get the clutch to the bite point with your other foot on the accelerator.
It would be illegal to use such a vehicle per TC
In theory, automatic handbrakes have a 'hill hold' function. That is, they put the rear brakes on for a moment until the car begins to move forward. But a number of vehicles with these things are poorly designed. The hill hold doesn't work, it comes off before many drivers are actually ready, or it stays on too long.
They are becoming more common, so watch for cars rolling back at junctions
“In some ways, it is easier to be a dissident, for then one is without responsibility.” ― Nelson Mandela, Long Walk to Freedom
meic wrote:The actual scenario was a car with an automatic handbrake. The driver can not keep the handbrake applied, the car automatically releases it and it does so before you can get the clutch to the bite point with your other foot on the accelerator.
It would be illegal to use such a vehicle per TC
In theory, automatic handbrakes have a 'hill hold' function. That is, they put the rear brakes on for a moment until the car begins to move forward. But a number of vehicles with these things are poorly designed. The hill hold doesn't work, it comes off before many drivers are actually ready, or it stays on too long.
They are becoming more common, so watch for cars rolling back at junctions
And yet it's possible to execute it properly (brilliantly even) like the Prii I used to drive. Push button to engage, auto-off on forward movement, never a roll, properly designed and engineered.
I'm not sure that "hill hold" is a part of what is being referred to as an automatic brake.
A lot of cars now have electronic handbrakes which are applied with a switch and are released the same way or by the car detecting forward movement. It seems to me that just like a traditional handbrake, if it's released and then you have to stop again, you must reapply the handbrake.
There is another function called "hill hold" which seems to be becoming more common, but by no means universal. My Audi automatic has the electronic handbrake but it does not have hill hold. I assumed that the hill hold was an optional feature of the automatic gearbox.
I don't think that any of this applies in the OP's case. The driver was doing the old, old thing of riding the clutch because they were too idle to apply the handbrake and they weren't as skilled as they thought, particularly when distracted by the arrival of a cyclist they had not allowed for. Bad driving and nothing more.
meic wrote:That sounds almost as good as a conventional cable operated handbrake.
I have to say, in some respects it was better. Pressing the P button puts Drive into Park. Pulling the wee lever back is straight into Drive and away you go.
Slightly disconcerting the first time, but totally intuitive thereafter.
Last edited by Bonefishblues on 12 Sep 2018, 9:35am, edited 1 time in total.
Got to be honest, all this 'automatic handbrake' guff surprises me. I'd thought a handbrake was supposed to also be a backup in case the main brakes fail (slightly more technical than a brick behind the wheel)? How is it a backup if its still tied into all the electronic gearbox gubbins?
brooksby wrote:Got to be honest, all this 'automatic handbrake' guff surprises me. I'd thought a handbrake was supposed to also be a backup in case the main brakes fail (slightly more technical than a brick behind the wheel)? How is it a backup if its still tied into all the electronic gearbox gubbins?
brooksby wrote: ... I'd thought a handbrake was supposed to also be a backup in case the main brakes fail ...
I think that even with the most basic modern car, the brakes are designed with so many safety features that the need to use the handbrake for emergency stopping is nil.
thirdcrank wrote:There is another function called "hill hold" which seems to be becoming more common, but by no means universal. My Audi automatic has the electronic handbrake but it does not have hill hold. I assumed that the hill hold was an optional feature of the automatic gearbox.
That can't be generally true. My Alfa manual has hill hold. Sadly, it needs a hill over 5% to activate and it only gives you two seconds to find the bite before it releases the brake anyway, so I feel I can't rely on it. I wonder how many roll-backs are drivers failing to find bite point quickly enough.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk All the above is CC-By-SA and no other implied copyright license to Cycle magazine.
Audi hold assist keeps the car stationary once it's stopped and automatically prevents it from rolling on uphill and downhill gradients. During stops on uphill and downhill gradients, Audi hold assist holds the car stationary for as long as needed. It's activated by pressing a button and allows the driver to set the car in motion smoothly without having to use the handbrake at all. If the vehicle remains stationary for a long period with Audi hold assist active, the system automatically switches over to the electromechanical parking brake. There's no need to operate the handbrake to pull away. Audi hold assist is part of the ABS-ESP control system. After you release the brake pedal, the hydraulic pressure is maintained, meaning the hydraulic system keeps the brake pads pressed against the brake discs at the front and rear. During this process, the electromechanical parking brake is not in operation. This means a quicker reaction time, less noise and less braking effect at all four wheels, and enhanced comfort. Audi hold assist is only available in conjunction with the electromechanical parking brake.
https://www.audi.co.uk/glossary/a/audi-hold-assist.html ==================================================================== PS I'll still take a lot of convincing that the OP's driver was anything other than lazy.
I wonder how it reacts to a false start, or a stall. It would have to psychic to know if the driver was trying to rock the car for some reason, back up a little bit deliberately or they had messed up.
