So ive had these roughly for around 2 yrs already... just curious to why this is happening to my rotors that thick black line? Please ur help is gladly appreciated. Get in here IHC lol

These are R1Concept rotors

 

funny thing is i have r1 concept rotors, and mine are doing the same thing except a little bit lower on the rotor closer to the hub

 

are you using oem pads?
after reading the other post , it seems this might be some sort of wear indicator for the rotors? i.e.visual indicator

 

Take a look at the pad in that area, anything unusual?

 

I doubt it. The slots are supposed to be the wear indicators.

 

I'm usin EBC Green pads... I will have to remove the pads and check them out cuz this is strange

 

kind of looks like your brake pads ain't touching that area

 

Although not pertinent to the OP question, thought I'd reply just for future reference, as the rotor thickness wear limit is very small, one wouldn't be able to detect that threshold by viewing the slotted area. As an example, the front M/T rotor when new is .98" and minimal allowable thickness is .91", so as one can see, once the rotor wears .07" or .035" on each side, the rotor is to be discarded. For those that are interested, the front A/T new 1.10", minimum 1.02", rear new .354", .30" minimum.

This is one reason why cutting the rotors are frowned upon as most shops will return a cut rotor that is actually under the service limit. They don’t mic the rotor to see if the limit has been breached, just cut and return. Most owners don't care as they are saving money by cutting the rotors as compared to new units. I consider rotors as throw away items, in most circumstances, just replace with new.

 

For future reference, please go and read up on the R1 rotors. The slots are indeed used as a wear reference:


Exclusive DIAMOND SLOTS; with R1 Concepts state-of-the-art Technology

* Triangular end points
* Provides for a smooth contact
* Eliminates brake debris at the end of slots
* Indicator of rotor wear

http://stores.ebay.com/R1Concepts/Brake-Rotors.html

 

I'll repeat, the slots are not utilized as a wear indicators. They state that the small triangular tips at the slot end is a good indicator of rotor wear, but they do not state that it is the factory service limit as designated by each OE manufacturer as it's just generic.

 

I'll repeat. The R1 concepts use the slots as a unique built-in wear indicator, therefore my statement stands that it's unlikely that the black stripe is a wear indicator. I'm not aware of any other rotors that utilize this form of wear indicator nor did I make any statement as to the accuracy or specificity of this advertised R1 Concept wear indicator.