This bike is new to me so I do not know the tire history. If this is a tread indicator I have never seen one like it. Tires actually look good.

 

No, it's not. Tread indicators lie in the tread groove itself.

No idea what that line is.

 

when I got a brand new tire, it had a color band like that. it quickly wore away. I have heard that it has something to do with identifying lot numbers at the factory or something to that effect.

is it strictly on the surface, or is it an actual groove in the rubber (rubbing on a bolt, etc)

 

It's a chicken strip indicator.

 

It's a indicator for manufacturer.

 

The tread wear indicator is inside the grooves (tread). Once you hit certain level of wear, you'll see a little rubber indicator inside the tread.

 

There are arrows on the tire sidewall pointing to the location (along the tire's circumference) of the wear bars.....

 

that looks like a brand new tire to me. looking at the treads, it looks like a whole lotta meat on that tire.

 

I agree on the tread depth. I just have never seen a stripe like that before. Does not want to rub off with a finger nail.

the only answer is to ride it more and see if it wears off. The line is too straight to be paint.

 

If it is a chicken strip indicator then it needs more curves