New rotors look weird

marvin1992 · 11-14-2015, 01:32 PM

So I got new rear rotors on my 335xi and they have like a giant inner ring and I don't know if that is normal or not. It is hard to explain so I took pictures. Sorry for the dirty rims. Picture 1 and 4 are the new rotors.[IMG][/IMG]

marvin1992 · 11-14-2015, 01:34 PM

2

marvin1992 · 11-14-2015, 01:35 PM

3

marvin1992 · 11-14-2015, 01:36 PM

4

avocet · 11-14-2015, 02:57 PM

Inner ring meaning the black painted area?
If so the brake disc has the parking brake mechanism in there... basically a small drum brake inside.

marvin1992 · 11-14-2015, 03:07 PM

Not the black part. The silver ring around the black hub. It's only in the 1st and 4th pic

avocet · 11-14-2015, 03:13 PM

That's just looks like the transition from the bare metal and the coating.

feuer · 11-14-2015, 09:31 PM

Quote:

Originally Posted by marvin1992

So I got new rear rotors on my 335xi and they have like a giant inner ring and I don't know if that is normal or not. It is hard to explain so I took pictures. Sorry for the dirty rims. Picture 1 and 4 are the new rotors.

You have that ring on the old rotors as well but is covered in rust.

marvin1992 · 11-14-2015, 09:32 PM

Quote:

Originally Posted by avocet

That's just looks like the transition from the bare metal and the coating.

Oh ok cool thank you

marvin1992 · 11-14-2015, 09:32 PM

Quote:

Originally Posted by feuer

Quote:

Originally Posted by marvin1992

So I got new rear rotors on my 335xi and they have like a giant inner ring and I don't know if that is normal or not. It is hard to explain so I took pictures. Sorry for the dirty rims. Picture 1 and 4 are the new rotors.

You have that ring on the old rotors as well but is covered in rust.

I see. I just was making sure because they looked different than the front older rotors. Thank you

Three_thirty_I · 11-16-2015, 08:50 AM

As mentioned, looks like the clean bare metal and coating that you are seeing - it will rust or get dirty in time and won't be as noticeable. For reference, this was what the new OE rear disks looked like on my 330i some years back:

andrey_gta · 11-16-2015, 09:58 AM

My rotors have a collection of rings on the surface.
They still perform great.

Jeff@TopGearSolutions · 11-16-2015, 11:39 AM

What have you done in regards to bedding in procedure?

Also what kind of pads and are they new or old?

marvin1992 · 11-16-2015, 10:50 PM

Pads and rotors were both brand new. From about 60mph I hit the brakes firmly without activating the abs. I did this about 8-9 times then drove awhile to let them cool off. I then used the brakes very lightly for the next 500 miles. Pads and rotors are both OEM

Three_thirty_I · 11-17-2015, 08:26 AM

Quote:

Originally Posted by marvin1992

Pads and rotors were both brand new. From about 60mph I hit the brakes firmly without activating the abs. I did this about 8-9 times then drove awhile to let them cool off. I then used the brakes very lightly for the next 500 miles. Pads and rotors are both OEM

That sounds about right. As long as you never came to a complete stop during each of those brake cycles and of course afterwards until they had cooled off.

When you fitted the new brake pads, did you compare the "footprint" of the old and new to make sure that they were the same size?

marvin1992 · 11-17-2015, 08:27 AM

The dealer did the install so I am not sure about that and I did not come to a complete stop as that would leave an imprint in the rotor

Three_thirty_I · 11-17-2015, 08:37 AM

Quote:

Originally Posted by marvin1992

The dealer did the install so I am not sure about that and I did not come to a complete stop as that would leave an imprint in the rotor

I think it's just a case of the disks and pads still have some more wearing in to do. But at the same time, the friction material does vary in places, so it could just be that current layer that has to still wear down that is causing that lighter inner bit. Does it feel rougher to the touch compared to the rest of the surface? I would just keep an eye on it. I seem to remember seeing a similar thing with mine.

11-14-2015, 01:32 PM	#1
marvin1992 Private 11 Rep 90 Posts Drives: 335i Join Date: Dec 2012 Location: U.S. iTrader: (0)	New rotors look weird So I got new rear rotors on my 335xi and they have like a giant inner ring and I don't know if that is normal or not. It is hard to explain so I took pictures. Sorry for the dirty rims. Picture 1 and 4 are the new rotors.[IMG][/IMG] Attached Images
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11-14-2015, 01:34 PM	#2
marvin1992 Private 11 Rep 90 Posts Drives: 335i Join Date: Dec 2012 Location: U.S. iTrader: (0)	2 Attached Images
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11-14-2015, 01:35 PM	#3
marvin1992 Private 11 Rep 90 Posts Drives: 335i Join Date: Dec 2012 Location: U.S. iTrader: (0)	3 Attached Images
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11-14-2015, 01:36 PM	#4
marvin1992 Private 11 Rep 90 Posts Drives: 335i Join Date: Dec 2012 Location: U.S. iTrader: (0)	4 Attached Images
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11-14-2015, 02:57 PM	#5
avocet Major 273 Rep 1,166 Posts Drives: 2007 328i 2011 X5d Join Date: Sep 2010 Location: Vancouver bc iTrader: (0)	Inner ring meaning the black painted area? If so the brake disc has the parking brake mechanism in there... basically a small drum brake inside.
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11-14-2015, 03:07 PM	#6
marvin1992 Private 11 Rep 90 Posts Drives: 335i Join Date: Dec 2012 Location: U.S. iTrader: (0)	Not the black part. The silver ring around the black hub. It's only in the 1st and 4th pic
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11-14-2015, 03:13 PM	#7
avocet Major 273 Rep 1,166 Posts Drives: 2007 328i 2011 X5d Join Date: Sep 2010 Location: Vancouver bc iTrader: (0)	That's just looks like the transition from the bare metal and the coating.
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11-16-2015, 08:50 AM	#11
Three_thirty_I Lieutenant Colonel 375 Rep 1,927 Posts Drives: 2010 BMW E90 330i M Sport Join Date: Aug 2010 Location: Cape Town, South Africa iTrader: (0) Garage List 2010 BMW E90 330i M ... [9.63]	As mentioned, looks like the clean bare metal and coating that you are seeing - it will rust or get dirty in time and won't be as noticeable. For reference, this was what the new OE rear disks looked like on my 330i some years back: __________________ 2010 BMW E90 330i M Sport (M) Ex: BMW E90 330i (M) '05 (His) \| (Hers) BMW E46 320i f/l (M) '03
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11-16-2015, 09:58 AM	#12
andrey_gta Brigadier General 318 Rep 4,040 Posts Drives: 130i coupé ;) Join Date: Nov 2011 Location: Bimmerpost iTrader: (1) Garage List 2008 BMW 128i [10.00]	My rotors have a collection of rings on the surface. They still perform great. __________________ 128i Sport 6MT converted to Euro 130i spec, 3.73 diff, tuned by evolve ~220 whp 207 wtq(ft-lb) SAE In-progress: //M front arm, M3 rack, e36M lip Wishlist: Coils, n55 mnts, headers, LSD, e60 finn diff "The 1-series is the last car that BMW engineered before the Germans, as a car-making culture, fell out of love with driving." - R&T 2013 135is
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11-16-2015, 11:39 AM	#13
Jeff@TopGearSolutions 3461 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	What have you done in regards to bedding in procedure? Also what kind of pads and are they new or old?
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11-16-2015, 10:50 PM	#14
marvin1992 Private 11 Rep 90 Posts Drives: 335i Join Date: Dec 2012 Location: U.S. iTrader: (0)	Pads and rotors were both brand new. From about 60mph I hit the brakes firmly without activating the abs. I did this about 8-9 times then drove awhile to let them cool off. I then used the brakes very lightly for the next 500 miles. Pads and rotors are both OEM
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11-17-2015, 08:27 AM	#16
marvin1992 Private 11 Rep 90 Posts Drives: 335i Join Date: Dec 2012 Location: U.S. iTrader: (0)	The dealer did the install so I am not sure about that and I did not come to a complete stop as that would leave an imprint in the rotor
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