Two brak calipers on one disc?

Thomas. PLease. · 29 Jan 2009 at 11:26

Hi there,

I've seen a fair few aston v8 vantage's around in the past, and have noticed that they appear to have on the rear disc, one large brake caliper in usually coloured, and a smaller black caliper like thing. I just wondered what this is used for?

Is it to clean the disc or to remove water, or what else could it be for?

Here is some pics i found on the internet.

Tom.

georges · 29 Jan 2009 at 11:27

For the handbrake.

paradigm · 29 Jan 2009 at 11:30

georges said:
For the handbrake.

Yep, it's for this.

ineed2upgrade · 29 Jan 2009 at 11:32

yup red caliper is hydraulically operated by the foot pedal and the black one is a mechanical handbrake caliper operated by the handbrake lever

Thomas. PLease. · 29 Jan 2009 at 11:33

A seperate caliper for the handbrake. So how does a normal car with just one caliper do the handbrake?

ineed2upgrade · 29 Jan 2009 at 11:36

because most rear disc cars have an internal handbrake mechanism on the inside of the disc operated by 2 brake shoes.others have a 2 in 1 rear caliper which works hydraulically and mechanically bu the bigger the discs the harder it is to make this work

Firestar_3x · 29 Jan 2009 at 11:37

It has either :

Shoes in the drum for a handbrake or A cable operated pull and rachet on the same caliper.

analog · 29 Jan 2009 at 11:41

I think the Maybach has two calipers on its front discs, but that's probably just to stop its huge weight.

mrk · 29 Jan 2009 at 11:44

Zonda has 2 huge Brembo callipers too.

paradigm · 29 Jan 2009 at 11:55

mrk said:
Zonda has 2 huge Brembo callipers too.

Is that "two huge" being "one large and one small"?

I see no second "huge" caliper, the black one is small.

Sone · 29 Jan 2009 at 11:57

you just jelous of the extra brembo's. I gbt you would stick one on the steering wheel if you could.

mrk · 29 Jan 2009 at 11:57

You haven't seen the size of the discs/wheels to say the black one is small.

Firestar_3x · 29 Jan 2009 at 11:58

Looks single piston and small to me :confused:

NathanE · 29 Jan 2009 at 12:02

Seems a bit pointless... added weight and cost.

Why don't they just do it like every other car does it? Have a rear caliper that supports both hydraulic and cable?

Firestar_3x · 29 Jan 2009 at 12:03

Because after the cars had a good spanking the large surface area of the pad is very warm, stop the car and clap the pad to the disc and you leave your wallet in all sorts of pain, having a much smaller surface area on a cold pad means its less likely to do this + it also means you don't get people running to Ferrari asking why my car has rolled down the hill.

Dup · 29 Jan 2009 at 12:04

NathanE said:
Seems a bit pointless... added weight and cost.

Why don't they just do it like every other car does it? Have a rear caliper that supports both hydraulic and cable?

I suspect it may be due to the heat of the brakes? These cars are designed to do some speed and the brakes would get tortured if you drove the cars properly. After a session, applying the handbrake on the same brakes you've just been abusing could cause a few problems with pads bonding to disc etc. Just a hunch though. It's usual track day advice for an average not to apply the handbrake will the brakes cool down so maybe this is just a posh track day aid?

NathanE · 29 Jan 2009 at 12:06

Firestar_3x said:
Because after the cars had a good spanking the large surface area of the pad is very warm, stop the car and clap the pad to the disc and you leave your wallet in all sorts of pain, having a much smaller surface area on a cold pad means its less likely to do this + it also means you don't get people running to Ferrari asking why my car has rolled down the hill.

Oh that is a good point

Good fool proof way to stop warped discs...!

Lashout_UK · 29 Jan 2009 at 12:13

Yea, barring the handbrake thing, you can run twin calipers too for braking reasons (or as many as you could fit if you desired!) - my Sprint has twin front calipers for example. This isn't a standard thing but the upright is designed to carry twin calipers and consequently it's a bolt-on job.

Problem is it enables you to dump so much heat into the disc and calipers that fade is reputedly increased - not that I've tried, yet!

Also increases unsprung mass but that's lessened if using aluminium calipers anyway.

Firestar_3x · 29 Jan 2009 at 12:17

Get some good quality ducts sorted out and it should help cool the disc, interested to see this lashout never heard of a car having the option to fit twin braking calipers.

paradigm · 29 Jan 2009 at 12:19

mrk said:
You haven't seen the size of the discs/wheels to say the black one is small.

You don't need to see it to judge size. As said, it is a single piston, floating caliper. By design it will be "small".