There were these hipster tires on Craigslist a while back.
Ive seen bicycle tires in other colors than black: Red, white, blue, even pink.
Other than white and green walls, I’ve only seen car tires in black.
Apparently not, but I’m still not convinced that mining cable has to endure the equivalent of 30K-50K miles of friction (plus the other issues, as constanze notes). Yes, certainly, it’s hard use (if not abuse), and it has to be extremely durable. I’m just not convinced that it’s equivalent to the hard use of an auto tire.
Rubber is used as the insulation in almost all medium voltage transmission cable. Usually a layered construction of an inner semi-conducting layer, then an insulating layer, then another semi-conducting layer.
The semi-conducting layers are rubbers with carbon black incorporated, the insulating layer is rubber with clay.
The wear on the tire treads really doesn’t matter for the color of the sidewall. Each part of the tire is a different rubber compound. The biggest drawback for colored sidewalls is the added mass needed to have the colored layer without compromising the integrity of the sidewall. There really isn’t too much demand for colored tires other than whitewalls or white lettering, so there isn’t much incentive to make them.
From what I’ve found (IANAM, found in a handful of promotional materials), the outer, protective jackets (the bit coming in contact with the mine surfaces) are not made out of rubber. Example (PDF):
Apologies if ‘Chlorinated Polyethylene’ is a type of rubber. I’ve never seen it on a package of Trojans.
If big wide whitewalls made a comeback, would cars start being manufactured with some high-tech variant of curb feelers to avoid scuffing them? I can just see little cameras mounted in the fenders.
Possibly, that was factor in the decreased popularity of whitewalls, too. If you scuffed your regular tire against the curb once in a while, it didn’t matter much.
A company called Tomahawk was selling motorcycle tires in a rainbow of colors. These were color in the rubber and not a coating. They no longer offer them, not sure if that is related to limited demand, or if there were issues with the tires themselves. They were apparently reman’s layed up on Metzler or Dunlop carcasses.
I recall Michelin used to make MTB tires in different colors as well. Doesn’t appear they do that any longer either. Makes me wonder if there just isn’t enough market for it to be worthwhile.