Has anyone looked at their pads/rotors on the 330i

CC 330i · 06-14-2005, 12:37 AM

I was looking at my calipers tonight and maybe I am just a newbie or something, but only the inside edge of the pad was contacting the rotor. The outer edge was more than 1/2 inch from the rotor, and it looked like the outside edge of the brake pad was much "thinner" than the inside edge. (Like it tapered down to a smaller thickness on the outside or something.

I am much more used to seeing the pads contact the rotors evenly even when not compressed by the caliper. It looked very odd to me to see just the inner edge of the pad contacting the rotor.

I am assuming that when compressed the pad "rotates" somewhat to contact the rotor evenly, but even still it looks like the outer edge or the rotor has less thickness. My rotors are getting even wear, so I can only assume this is normal but it freaked me out.

Can anyone comment, or am I just crazy?

CC 330i · 06-14-2005, 03:32 PM

Anyone?

Gnosis · 06-14-2005, 03:41 PM

No idea... I haven't even collected my car yet... but if you get even wear on the pads I suppose that everything must be the way it's supposed to.

Sounds freakish though... why would BMW construct it like that??? Maybe to prevent debris build up? Add extra cooling to the pads? Hmmm.....

CC 330i · 06-14-2005, 03:46 PM

It almost looks like uneven wear on the pad, but even wear on the rotor. I had a friend today at lunch start my car and depress the brake pedal while I looked at the pad/rotor, and it never fully contacted the rotor uniformly. Only the inner edge of the pad on both front wheels. The rears looked like they uniformly contact the rotors.

Maybe the car knows when it is in motion and squeezes the brakes more forcefully when necessary to make them come in contact with the entire surface of the rotor. It just looks weird at a stop!

E90Fleet · 06-14-2005, 04:24 PM

you are not getting confused with the beveling on the pad edges ( they are sloped at a angle like on the pic below )

They are supposed to be like that

CC 330i · 06-14-2005, 04:34 PM

OK, maybe that's it... Thank you. Maybe toward the middle of the pad the entire surface is in contact with the rotor. but on the sides of the pad, due to the bevel (or chamfering) the pad looks like it is not fully in contact.

It just looks like the inner edge of the pad is only making contact from where I can see through the wheel.

(For example if the "I" is the rotor and the "V" is the pad, it looks like this: VI

where the top of the "I" the inner portion of the rotor closest to the hub. The angle of reference would be from the front of the rotor, not the side).

E90Fleet · 06-14-2005, 04:43 PM

I think you are seeing the bevel/chamfering, its more obvious when the pads are new

When looking at the brake pad from the front of the car towards the rear the top ( towards the roof) and bottom (towards the ground) edges dont innitally touch the rotor only the middle section touches. As the pad wears the top and bottom sections will start touching aswell.

The rear pads generally have little or no beveling

Gnosis · 06-14-2005, 04:43 PM

Some brake systems a designed to make use of the rotating force that is applied to the pads. The pads are then squeezed tighter to the rotor with less brake fluid pressure.

It is possible that your pads will move in differently on the rotors when everything is turning... Ask your friend to drive you around town and brake some while you hang under the car on a "mech-slider".

CC 330i · 06-14-2005, 05:23 PM

Quote:

Originally Posted by E90Fleet

I think you are seeing the bevel/chamfering, its more obvious when the pads are new

When looking at the brake pad from the front of the car towards the rear the top ( towards the roof) and bottom (towards the ground) edges dont innitally touch the rotor only the middle section touches. As the pad wears the top and bottom sections will start touching aswell.

The rear pads generally have little or no beveling

OK, I think I am getting it, but to me it looks like the pad is touching at the bottom (towards the ground) but not at the top (towards the roof) at the front of the pad. It must just the angle I am looking at it though... Thank you for the responses!

CC 330i · 06-14-2005, 05:25 PM

Quote:

Originally Posted by Gnosis

Some brake systems a designed to make use of the rotating force that is applied to the pads. The pads are then squeezed tighter to the rotor with less brake fluid pressure.

It is possible that your pads will move in differently on the rotors when everything is turning... Ask your friend to drive you around town and brake some while you hang under the car on a "mech-slider".

That sounds kinda fun!

Well at least the brakes work great, weird looking or not!

06-14-2005, 12:37 AM	#1
CC 330i Captain 44 Rep 722 Posts Drives: 330i SG/Blk/Alum Join Date: May 2005 Location: Orange County, CA iTrader: (0)	Has anyone looked at their pads/rotors on the 330i I was looking at my calipers tonight and maybe I am just a newbie or something, but only the inside edge of the pad was contacting the rotor. The outer edge was more than 1/2 inch from the rotor, and it looked like the outside edge of the brake pad was much "thinner" than the inside edge. (Like it tapered down to a smaller thickness on the outside or something. I am much more used to seeing the pads contact the rotors evenly even when not compressed by the caliper. It looked very odd to me to see just the inner edge of the pad contacting the rotor. I am assuming that when compressed the pad "rotates" somewhat to contact the rotor evenly, but even still it looks like the outer edge or the rotor has less thickness. My rotors are getting even wear, so I can only assume this is normal but it freaked me out. Can anyone comment, or am I just crazy?
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06-14-2005, 03:32 PM	#2
CC 330i Captain 44 Rep 722 Posts Drives: 330i SG/Blk/Alum Join Date: May 2005 Location: Orange County, CA iTrader: (0)	Anyone?
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06-14-2005, 03:41 PM	#3
Gnosis Private 21 Rep 90 Posts Drives: 330i on order :-) Join Date: May 2005 Location: Earth iTrader: (0)	No idea... I haven't even collected my car yet... but if you get even wear on the pads I suppose that everything must be the way it's supposed to. Sounds freakish though... why would BMW construct it like that??? Maybe to prevent debris build up? Add extra cooling to the pads? Hmmm.....
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06-14-2005, 03:46 PM	#4
CC 330i Captain 44 Rep 722 Posts Drives: 330i SG/Blk/Alum Join Date: May 2005 Location: Orange County, CA iTrader: (0)	It almost looks like uneven wear on the pad, but even wear on the rotor. I had a friend today at lunch start my car and depress the brake pedal while I looked at the pad/rotor, and it never fully contacted the rotor uniformly. Only the inner edge of the pad on both front wheels. The rears looked like they uniformly contact the rotors. Maybe the car knows when it is in motion and squeezes the brakes more forcefully when necessary to make them come in contact with the entire surface of the rotor. It just looks weird at a stop!
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06-14-2005, 04:24 PM	#5
E90Fleet Lieutenant General 1312 Rep 10,185 Posts Drives: BMW Join Date: Apr 2005 Location: South Africa iTrader: (0)	you are not getting confused with the beveling on the pad edges ( they are sloped at a angle like on the pic below ) They are supposed to be like that
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06-14-2005, 04:34 PM	#6
CC 330i Captain 44 Rep 722 Posts Drives: 330i SG/Blk/Alum Join Date: May 2005 Location: Orange County, CA iTrader: (0)	OK, maybe that's it... Thank you. Maybe toward the middle of the pad the entire surface is in contact with the rotor. but on the sides of the pad, due to the bevel (or chamfering) the pad looks like it is not fully in contact. It just looks like the inner edge of the pad is only making contact from where I can see through the wheel. (For example if the "I" is the rotor and the "V" is the pad, it looks like this: VI where the top of the "I" the inner portion of the rotor closest to the hub. The angle of reference would be from the front of the rotor, not the side).
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06-14-2005, 04:43 PM	#7
E90Fleet Lieutenant General 1312 Rep 10,185 Posts Drives: BMW Join Date: Apr 2005 Location: South Africa iTrader: (0)	I think you are seeing the bevel/chamfering, its more obvious when the pads are new When looking at the brake pad from the front of the car towards the rear the top ( towards the roof) and bottom (towards the ground) edges dont innitally touch the rotor only the middle section touches. As the pad wears the top and bottom sections will start touching aswell. The rear pads generally have little or no beveling
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