Brakes - Surface Area
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Brakes - Surface Area
How important is it to have a large surface area on disc brakes? I've seen some brake upgrades that advertise better stopping power with bigger discs than standard but the contact patch with the pads is smaller than the original pads. How does that work? :/
For example, I've just put some bigger brakes on my Mondeo, 30mm bigger infact but garage phoned me up saying the pads are smaller than the ones I had on originally.
For example, I've just put some bigger brakes on my Mondeo, 30mm bigger infact but garage phoned me up saying the pads are smaller than the ones I had on originally.
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Joined: Jun 2003
Posts: 12,970
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From: West Mids
Not sure of the correct terminology but if you have a piston pushing on a pad with a big area it will put less force on the disc than a smaller pad.......ie its the same force but over a smaller area...depending on the qualities and operating temp of the brake pads the smaller one could perform better as i guess it would generat more friction and therefore heat..the larger discs will dissipate heat away more quickly than smaller ones keeping performance more consistent and reducing fade
the surface area of the disc means it is able to disapate more heat
the bigger a disc the more leverage it can exert
the bigger the pad area the bigger clamping force you can apply to the disc surface
if you have a, for example, 240mm disc with suitable calipers and then upgrade to, for example, 283mm discs but use the same calipers, for the same amount of pedal pressure you will stop much quicker as you are using effectivly a longer lever to apply the pressure to the tyres to slow them down
if you add it all up, biger surface area, bigger amount of pistons in the caliper to spread the load better, bigger discs and a much larger surface area on which to apply the pads the rise in braking rises exponetioaly
the other thing is that certain groups decide that you can only limit the amount of braking by the grip on the tyres, but they tend to forget the fact that the more you break the more the weight shifts to the front of the car, loading up the suspension and giving you more grip onthe tyres, which means you can havemore braking
don't believe me? i put a set of 330's and 4 pots on the seirra and noticed that the suspension top mounts were starting to poke through the tops of the turrest, soemthing that never happened even when i was running 300mm's
the bigger a disc the more leverage it can exert
the bigger the pad area the bigger clamping force you can apply to the disc surface
if you have a, for example, 240mm disc with suitable calipers and then upgrade to, for example, 283mm discs but use the same calipers, for the same amount of pedal pressure you will stop much quicker as you are using effectivly a longer lever to apply the pressure to the tyres to slow them down
if you add it all up, biger surface area, bigger amount of pistons in the caliper to spread the load better, bigger discs and a much larger surface area on which to apply the pads the rise in braking rises exponetioaly
the other thing is that certain groups decide that you can only limit the amount of braking by the grip on the tyres, but they tend to forget the fact that the more you break the more the weight shifts to the front of the car, loading up the suspension and giving you more grip onthe tyres, which means you can havemore braking
don't believe me? i put a set of 330's and 4 pots on the seirra and noticed that the suspension top mounts were starting to poke through the tops of the turrest, soemthing that never happened even when i was running 300mm's
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Joined: May 2003
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From: Newbury
the surface area of the disc means it is able to disapate more heat yup
the bigger a disc the more leverage it can exert the futher the caliper is from the centre of the disk you mean
the bigger the pad area the bigger clamping force you can apply to the disc surface Nope - bigger surface area = lower pad temps and lower wear rates
Surface area and friction are complete unrelated!
Alex
the bigger a disc the more leverage it can exert the futher the caliper is from the centre of the disk you mean
the bigger the pad area the bigger clamping force you can apply to the disc surface Nope - bigger surface area = lower pad temps and lower wear rates
Surface area and friction are complete unrelated!
Alex
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