Tread

The tread of a tire or track refers to the rubber on its circumference that makes contact with the road or the ground. As tires are used, the tread is worn off, limiting its effectiveness in providing traction. A worn tire can often be retreaded.

The grooves in the tire are correctly called the tread pattern, or simply the pattern, but the word tread is often used casually to refer to the pattern of grooves molded into the rubber. The grooves are not the tread, as they do not make contact with the ground. This distinction becomes significant in the case of racing slicks: which certainly have a tread but do not have grooves, and so they neither have a pattern.

Tires

Street tires

The grooves in the rubber are designed to allow water to be expelled from beneath the tire and prevent hydroplaning. The proportion of rubber to air space on the road surface directly affects its traction. Design of tire tread has an effect upon noise generated, especially at freeway speeds. Generally there is a tradeoff of tread friction capability; deeper patterns often enhance safety, but simpler designs are less costly to produce and actually may afford some roadway noise mitigation. Tires intended for dry weather use will be designed with minimal pattern to increase the contact patch. Tires with a smooth tread (i.e., having no tread pattern) are known as slicks and are generally used for racing only, since they are quite dangerous if the road surface is wet.

Transformers: The Veiled Threat

Transformers: The Veiled Threat is a science fiction novel set in between the events of the 2007 movie Transformers and its 2009 sequel Transformers: Revenge of the Fallen. Alan Dean Foster, author of another Transformers novel and the novelizations of both movies, is the author of this novel also. The 304 page paperback novel was released April, 2009. Foster is an established science fiction writer, having written a large number of novels for both original and existing media properties such as Aliens, Star Trek, and Star Wars.

Plot

Present-day, Megatron lies dead, at the bottom of the sea. Cut to the Gulf of Aden where pirates attack a freighter which just so happens to be ferrying Epps, Lennox, Ironhide, Ratchet, and other NEST (Networked Elements: Supporters and Transformers) members to their base on Diego Garcia. Ironhide soon transforms to robot mode and scares the pirates off. Arriving at Diego Garcia, the boys meet up with cybernetics expert Kaminari Ishihara, who has been swimming in the lagoon with the newly arrived Autobot veteran Longarm serving as lifeguard. Everyone enters a briefing where a sighting of Starscream in Zambia is discussed and a plan is hatched with Optimus Prime to confront him.