I saw a discussion on another forum about the "unswept" area of brake rotors, specifically how many people prefer to paint those areas to keep them from rusting. One person was complaining about the 1/4" or maybe 3/8" "ring" on his rotor. Then I looked at the rear rotor on my car. Only a little more than half of the rotor seems to be contacted by the brake pad (see attachment).

Does this vary based on the pads used ? I bought this car from my sister and have most of the service records. She had all work done by Infiniti other than replacing tires as well as rear brakes done 60k miles ago by an independent shop. My sister actually mentioned having another brake job done within the past 6 months but I don't know if it was the front or rear (will try and find out). So, I don't know what pads these are or who did them but I'm leaning towards it being the independent shop.

Does this look similar to what the factory pads cover ? Anyone know of pads that cover more area ?

 

Never heard of someone using a wider pad. But just get rotors with a protective coating. Centric premiums are affordable and claim they can stand 400 hours in salt water. There is still a small area exposed but nothing like your current rotors. Rotors will rust overnight but the minute you use your brakes it cleans that layer off. Front
Rear

 

After you put some miles on new rotors it's clear where the exposed area is that's not touched by the pads. Additionally, you could mask around that area and paint it as well and have almost a rust free rotor

 

Either the rotor fits another application with a larger swept area, or the e-brake assembly fits another application so they had to keep the ebrake drum small (so they filled the rest of the space with unused disc). I'm guessing it's the rotor one though, since that would be much less expensive on a large production scale. I can almost guarantee there is no pad that would fit the stock sliding rear caliper AND fill out the entire annulus.

 

I know they'll rust on the non-contact areas and on the current rotors, there's nothing I can really do. Well, I could pull the calipers and paint them but I'd have to remove the existing rust and I'm not going to that trouble. When they get replaced - no idea how soon that may be - I will either paint the rotors beforehand or get coated rotors. I actually have Centric's "premium" coated rotors on my "G35" shopping list at Amazon for the time that's necessary. I just put Raybestos' RPT rotors on the front of my wife's Fusion - too soon to say how they'll hold up though.

Your 2nd picture is the rear, right ? Your pad definitely covers more rotor than mine. I know the rear brakes were replaced at least once by an independent shop so it's unlikely they used Nissan pads. Makes me think the aftermarket pads are smaller than the OEM pads from looking at yours. What year/model do you have ? What pads are those ?

Thanks !

 

They are the rears. They are akebono pro acts and very pleased with them. The actually part of the rotor that the pad bites looks the same as yours. That dull part of my rotor will rust eventually. Only been on the car a couple weeks now

 

You're right. Just checked p/n 43206-EG000 and it shows that it fits at least (138) different Nissan and Infiniti applications, all the way up to a '17 QX50 or '17 370Z and back to '05 G35 and other models. There always are trade-offs when that happens but I completely get why Nissan would share parts like this.

 

Now that I look closer, I see that on the pad contact portion. The "hat" portion doesn't have the same coating though ?

 

The black portion is the protective coating. For a full rust free rotor you'd have to paint that dull area just outside of the hat that the pads don't touch

 

Gotcha. The area outside the pad contact area just hasn't rusted yet (but will).

The coated rotors I put on my wife's car are in the attached image. It's definitely a different type of coating.