Kinda of a stupid question ... but whats the best indication when it's time to replace the rotors? I'm getting a pretty distinct lip on the outside of the front rotors.

 

Got vibrations in the brake pedal when braking hard, like in autoX or exiting the freeway? Time to machine the rotors down if the metal is within spec.

For street stuff you can measure the rortors with a micrometer and check the specs in the shop manual if you have one.

For road racing I replace my rotors after 3 race weekends.

 

I replace them when the lip is large or if they're cracked (all the way through).

Warren

 

when they get smaller than they are allowed to get (see the manual for measurement)

or when they crack.. or have been hosed down with a fire extinguisher
or when your wheel falls off and it drags on the ground
or when a race official determines they are illegal.

 

When they look like this...

https://honda-tech.com/zerothread?id=181691

The lip is not that big of a deal with me... it only means that the pads have less rotor mass to use... and the cracking will get worse at a quicker rate

Will

[grammer]


[Modified by Willard, 1:43 PM 5/16/2002]

 

When they look like this..

Or if the steering and dash shake violently under heavy braking.

 

JINX!!!

 

DAMN! off by a few seconds.. and same pic too! You must drink more

 

I've only got superficial cracks and these rotors are still good to go. As a matter of fact they've never felt better. I could probably still track them (if I wasn't upgrading to larger rotors/calipers in a few weeks).

 

I admit that I was a little shocked when the folks at Wilwood told me that rotors that look like the last picture above are still OK...

Kirk

 

I have not looked at the rotors at operating temp..... but I would think the cracks would loose some size with heat applied to the rotor....

But when the cracks go thru the disc... or collect pad material... then it is time to toss them.

Willis