When to replace drag radials

[futuretech]

Miy Nitto 555r's are down to the treadwear indicators but still grip good. How long can I expect decent traction at the track?

[ZRWHAT]

As long as they still hook and no cords are showing, use them all the way up. You'll know when they stop hooking.

Monitor the cord thing closly and sometimes its just a judgement call, if a little voice says "they're Done" listen to that voice....