Thread: Use of handbrake on downhill

Originally Posted by drivesafe

Again, anyone with a D3 or RRS, DO NOT try this. The electronically activated park break does not operate in the same manor as a conventional hand break.

Cheers

What happens if you activate this on a RRS/D3/etc? Big damage?


BTW - Who would have thought a thread on handbrakes could get this long!

Originally Posted by spudboy

What happens if you activate this on a RRS/D3/etc? Big damage?

No damage to the brake but you can only have the handbrake on or off as it's electrically operated. No halfway in between.

So, lets say your main brakes fail - if you activated it at, say, 50 Km/h would it slow you down at all?

Originally Posted by spudboy

So, lets say your main brakes fail - if you activated it at, say, 50 Km/h would it slow you down at all?

Yes, at speed it won't actually lock on but will bring the car to a stop (supposedly).
I might give it a go when I next drive a loaner .

Well that's useful I guess.... how does it know how hard to apply itself?

Will be interested to hear if anything goes bang when you try it.

Originally Posted by spudboy

Well that's useful I guess.... how does it know how hard to apply itself?

It has it's own control module (surprise, surprise) so hopefully it can work it out.

Will be interested to hear if anything goes bang when you try it.

So will I .
I know the warning chime goes off it's dial when you flick the switch while driving but it needs to be held for a few seconds to activate the handbrake.

Originally Posted by Rosco

To set the record straight .........

45 deg = 100% (1 in 1) ... i.e. (1/1)*100 = 100%
90 deg = infinity% (1 in 0) ... (1/0)*100 = infinity%
60% = 1 in 1.66667 = 31 deg
40% = 1 in 2.5 = 21 deg

Cheers

For anyone further interested in the conversion of gradient to degrees and the relation between the two, a link to a simple online conversion program.
Ignore the other variables unless they interest you.
Simply input the % or angle you wish to convert and ENTER
At a glance the above information is correct. Reduce your results to 2 significant figures to simplify resuts
http://www.cactus2000.de/uk/unit/massgrd.shtml

The important one to remeber is 100% =45 degrees
This only works with horizontal being 0 degees, as horizontal can also have the value of 90 degrees in a vertical circle

Originally Posted by spudboy

What happens if you activate this on a RRS/D3/etc? Big damage?

Actually, if you do it on an auto, the hand brake will automatically disengage.

If you try it with one of the Terrain Response programmes on then you'll be OK until the centre diff engages (which'll probably be almost instantly) and then it's down to which is the weakest component!!! (The hand brake on the D3 & RRS is effectively a motorized drum brake inside the rear hubs).

M