Hub-and-spoke conspiracy involving other actors who are cooperating with the hub in carrying out the scheme. It is controversial, particularly in the antitrust cases, how much knowledge spoke actors must have of the conduct of other spoke actors—which is to say how much of a "rim" must be put around the "wheel" of the hub-and-spoke conspiracy for it to be a single conspiracy rather than many separate "vertical" conspiracies. There is a controversy and some uncertainty over the legal status of the "rimless" conspiracy—one with very limited interaction among the spokes. The leading two Supreme Court cases were "Interstate Circuit" and "Kotteakos".
Tire Wear bars (or wear indicators) are raised features located at the bottom of the tread grooves that indicate the tire has reached its wear limit. When the tread lugs are worn to the point that the wear bars connect across the lugs, the tires are fully worn and should be taken out of service. Most wear bars indicate a remaining tread depth of and are tires are deemed "worn out" when the tread is worn down to that point. The tire bead is the part of the tire that contacts the rim on the wheel. The bead is typically reinforced