Brake Caliper Position - Which Is Best?

[T9 man]

Hopefully someone can explain to me, why is it that some brake calipers are mounted at the front of the disc and some are mounted at the rear of the disc.

Is it a performance or a space related thing? are there any unique advantages or disadvantages to either position?

 

[HDi fun]

I'm not aware of any technical merits of either arrangement, the brakes create a torque which rotates [against the direction of travel] about the axis of the hub/wheel assembly regardless of where they're mounted.

Therefore I imagine that it's less to do with suspension geometry and the practicalities of accomodating all the other components.

 

[old-git]

Googled this and I am none the wiser

Personal preference would be both inboard in order to reduce angular momentum (I thnk that is the right phrase) - ie bring the weight closer to the CoG.

Keepig the hot caliper away from suspension and steering joints is a consideration as well as where they will actually fit.

 

[lutonmatt]

i normaly find as long as its on the discs it dont matter
its when they are fitted in the glove box you have problems lol

 

[T9 man]

There's always one!

 

[turbonutter69]

 

[MasterAuron]

I suddenly pondered this the other day, the disc is round to it doesn't matter where the pads stop it was the conclusion I came to. OG raises a good point about weight distribution too though.

 

[old-git]

I have seen it suggested:

If the caliper is at the front, the disc will try to force the caliper down, pushing the suspension into the road. With the caliper at the back, the disc will try to lift the caliper up and along with it the wheel.

Anybody got any views on this - HD?

 

[lutonmatt]

There's always one!

i do try
bet you really missed me when i was not here

 

[turbonutter69]

I can't quite see how that is possible OG??

 

[MasterAuron]

Nor me. I think I see what you are trying to say but weight transfer of the car onto the suspension under braking would stop it surely shirley?

 

[old-git]

Nor me. I think I see what you are trying to say but weight transfer of the car onto the suspension under braking would stop it surely shirley?

I have no idea, that's why I asked.

 

[MasterAuron]

I have no idea, that's why I asked.

We are all clueless then If none of us know, it can't make a difference. Majority rule and all that :bigsmile:

 

[T9 man]

Well this has got be a first for me on TC! :blink:

 

[Loz]

Has anyone ever noticed that some super cars, the rear wheels have two sets of callipers? One is the main calliper the other I assume is a handbrake. :amuse:

 

[T9 man]

Has anyone ever noticed that some super cars, the rear wheels have two sets of callipers? One is the main calliper the other I assume is a handbrake. :amuse:

Have never seen this, any car in particular Loz?

 

[HDi fun]

In response to OG's post:-...

The [reverse, braking] torque is rotating about the hub against the direction of travel, regardless of where the caliper is mounted.

Whether the caliper is mounted ahead of or behind the steer axis plays no part. Weight transfer when braking is the same.

The caliper is an unsprung mass, it's fixed to the [unsprung] hub, not to the sprung mass of the car.

 

[Loz]

Have never seen this, any car in particular Loz?

Lamborghini's I noticed it on.

 

[SLEEPER]

One of the calipers is almost certainly the handbrake.

Re the position of the caliper.
Loking at F1 cars usually gives the "best " position
all cars inc F1 I have ever seen mount them 3 or 9 o clock so the answer must be pretty basic
I imagine this is ground clearance and suspension travel with the other options.

keeping the calipers out of the way is my best guess

 

[claymore]

I have often wondered if it would be possible to fit two calipers on a disc instead of going to bigger disks (for fitting under smaller wheels)

 

[HDi fun]

Two calipers would reduce the amount of disc surface area available for cooling

 

[old-git]

Just spoken to my race car builder friend and he is not aware of any positional advantages other then CofG.

 

[HDi fun]

Just spoken to my race car builder friend and he is not aware of any positional advantages other then CofG.

My mind was leaning that way, too.

Keeping as much of the mass as far inboard as possible does make sense for all applications.

So unless other suspension components force the calipers to be outside of the axle then inside it is.

Thanks.

 

[T9 man]

Just spoken to my race car builder friend and he is not aware of any positional advantages other then CofG.

Marvellous, many thanks OG.

 

[lima4specter]

Googled this and I am none the wiser

Personal preference would be both inboard in order to reduce angular momentum (I thnk that is the right phrase) - ie bring the weight closer to the CoG.

Keepig the hot caliper away from suspension and steering joints is a consideration as well as where they will actually fit.

The weight of the calipers is unsprung weight which does and doesnt (its a little confusing even to us who've been engineering and building cars for a while) effect the CoG. Ideally, you want the calipers to add angular resistance to the rotors in such a way as that they are perpendicular to the tire patch which will result in maximum torque working against the angular velocity of the wheels/rotors.

The placement of the calipers, as it pertains to the left or right side when looking at the rotor, has everything to do with overall structure and placement of other items (ie caliper bracket vs strut/shock mounting, tie rods, etc.) with a minor role in styling.

Hope this helps.