Before tread depth indicators were "invented".
 

...how did you know "it was time"?

Re: Before tread depth indicators were "invented"....
 

Re: Before tread depth indicators were "invented"....
 

what's a tread depth indicator ;) i alway's use the same as above :D

Re: Before tread depth indicators were "invented"....
 

If you can see the canvas, you've got about a thousand miles left in 'em.

Re: Before tread depth indicators were "invented"....
 

Rather than having a tyre maker tell you there was one millimetre left, you looked for yourself.

:confused:

Re: Before tread depth indicators were "invented"....
 

Penny?

Something about seeing the Queen's head = replacement time (1mm is the distance from the edge of the coin to the crown) or something along those lines.

Re: Before tread depth indicators were "invented".
 

JUst wondered - i'm down to the indicator now anyway.