I have the stoptech bbk, and I have loads of radial hairline cracks. I'm accustomed to seeing these in stock rotors, but didn't expect to see them with the stoptech bbk.

I do have ducting. These rotors have about 14 days on RE-11s and one day on NT01s.

Are others with the bbk developing these hairline cracks?

 

My RacingBrake stock size rotors developed hairline cracks early and I freaked, but I ended up getting 24 hard track days on them before they actually cracked so you'll probably get a lot more track time on your rotors.

 

My Stoptech Trophy kit has 6 full weekend races on them (practice 30mins, Qualifying 20mins, Race 45mins) , slight hairline cracks. I'll probably replace the rotors before next season just for piece of mind. I only just put ducting in for the final weekend. I'm hard on brakes too so I'm amazed they lasted this long. Still haven't killed the first set of pads yet either. DTC70's and only about half worn. I was killing one set of stock rotors per weekend and a set of pads every other weekend.

 

Thanks for the replies.

I'm hard on brakes as well, but I was hoping with ducting AND a bbk that the rotors would last much longer.

I guess I'll be replacing these rotors soon for piece of mind as well.

As an aside, I blew my master cylinder this past weekend. It only had 39k on it.

 

Don't be too hasty with replacing those rotors. The hairline cracks showed up with over 70% of their life left, and when it did crack it was a small crack shown below.

 

Might want to check with Vooper. He has been tracking the StopTech kit for a couple of years...

 

turbo8765 do you have any pics of the cracks?

 

I wouldn't be jumping on the hairline cracks as that big a deal. I mean I was a bit surprised when doing an oil change on my truck the other day to find hairline cracks on my trucks rotors all thoughout with 20k on the brakes..... and it's a truck for crying out loud.

 

I used a stoptech BBK on my Evo for several years. Hairline cracks develop pretty soon. Nothing to worry about until they start joining together into bigger cracks that nearly reach from the inside to the outside of the rotor. If that happens and you can get your fingernail caught in the crack, time to order a new set of rotor rings and be prepared to change them at the event.

 

I wouldnt replace it until a crack goes radially to the outside edge or near the inner mounting tab. If those places are fine keep running it. Hairline cracks are common and usually nothing to worry about.