[Mister Tee]

When they get too thin they will start warping and overheating. If they are "at" their minimum thickness, then technically they are at the end of their life. How much more you can squeeze out of them depends on your riding style and braking habits.

 

[Mister Tee]

Rotor should have minimum allowable thickness stamped right on them near the hub... Mine says minimum of 5.0mm on my 04 1K.... They are original with 25k miles and are currently at 5.27mm... I have no idea how thick they are new?

Can you mike an unworn edge of the rotor?

Most motorcycle rotors come with about 0.5 mm over minimum thickness (4.5 mm, 4.0 mm minimum thickness.)