80% tread requirement

[Rydell]

Hey folks, maybe you could help me out here. I've got a front tire with less than 1k of street riding miles. Looks to be above 80% but last thing I want to have happen is get rejected and sent home on my first track day for having a 70% tire. Could you enlighten as to how you guys go about measuring the tire tread life?

[Farzanegan]

There is a tire vendor at the track...