How to know if you have 1/2 o more tread life remaining?

[Flash]

A one day track school I have been thinking about doing requires "Tires with half or more tread life remaining":
http://www.lonestartrackdays.com/html/requirements.html#bike

How am I supposed to know that? I would hate to show up and be turned down on the spot. Is there some universal tread life that all motorcycle street tires have or is it specific to each brand/model?

Here is what I currently have:
front -> Metzler ME330 (110/70)
rear -> Metzler ME550 (130/70)

[GRU]

at work we use a little tool that we put between the tread and shows a number */32........like new tires are usualy 10/32 for cars....some truck tires with big tread are 16/32....

just go to wal-mart and buy that tool....i would think that new motorcycle tires have tread about 8/32 (maybe less) and if your tire tread measures less then 4 then you need new tires

[TR]

Owner's manual says 0.06 in front and 0.08 in rear to be the minimum tread depth for the stock tires, since a new tire is around 0.25 in depth, tire life is around 0.19 in, and therefore, a tire with at least 1/2 life would have 0.15 in left. These are only general figures, if your tires have a deeper tread you can now make your own calculations.

Good luck at the track school.

[gsJack]

A one day track school I have been thinking about doing requires "Tires with half or more tread life remaining":
http://www.lonestartrackdays.com/html/requirements.html#bike

How am I supposed to know that? I would hate to show up and be turned down on the spot. Is there some universal tread life that all motorcycle street tires have or is it specific to each brand/model?

Here is what I currently have:
front -> Metzler ME330 (110/70)
rear -> Metzler ME550 (130/70)

You can buy a tread depth guage at almost any auto parts, Walmart, etc store. They are very inexpensive and most read in both 32nd inches and in mm.

A new ME330 has 4.4 mm deep tread in 110/70 size and a new ME550 has 6.8 mm deep tread in 130/70 size, according to Metz specs.  New tread depth varies considerably for different tires and brands.  MEZ2 in 130/80 has 8 mm deep tread depth when new for example.  My Avon 140/80 AV36 had only 5 mm of rear tread new.