Hydroplaning becomes more prevalent with wider tires (because of the lower weight per contact area) andespecially at higher speeds; it is of virtually no concern to bicycle tires under normal riding conditionslargely because of the lower speeds. The chance of car hydroplaning is also minimal at bicycle speeds asthe weight per contact area of car tires is not much lower if any than bicycle tires.
25/12/2015Tire Wikipedia, the free encyclopedia26/32Tire showing weathercracking overlongterm exposure to the weather.A child plays in a playground madefrom recycled tires. Guelph, OntarioDangers of aged tiresResearch and tests show that as tires age, they begin to dry out and become potentially dangerous, even ifunused. Aged tires may appear to have similar properties to newly manufactured tires, but rubber degradesover time, and once the vehicle is traveling at high speeds (i.e. on a freeway) the tread could peel off,leading to severe loss of control. In tropical climates, tires degrade sooner than in temperate climates, andmore care should be taken in these climates to ensure that tires do not fail. Also, tires on seldomusedtrailers are at the greatest risk of agefailure, but some tires are built to withstand idleness, usually withnylon reinforcement.Many automakers recommend replacing tires after six years, andseveral tire manufacturers (Bridgestone, Michelin) have called fortires to be removed from service 10 years after the date ofmanufacture. However, an investigative report by Brian Ross onABC's 20/20 news magazine found that many major retailers suchas Goodyear, WalMart, and Sears were selling tires that had beenproduced six or more years ago. Currently, no law for aged tiresexists in the United States.Scrap tires and environmental issuesOnce tires are discarded, they are consideredscrap tires. Scrap tiresare often reused for things from bumper car barriers to weights tohold down tarps. Some facilities are permitted to recycle scrap tiresthrough chipping, and processing into new products, or selling thematerial to licensed power plants for fuel. Some tires may also beretreaded for reuse. One group did "a study to evaluate thepossibility of using scrap tires as a crash cushion system. Theobjective of this study was to evaluate the material properties ofused tires and recycled tirederived materials for use in lowcost,reusable crash cushions".An interesting use, developed over 30 years back but not yetuniversally used, is to process scrap tires as raw material for roads. The process is removing the metal,granulating the rubber and then a chemical process where it is mixed with other usual materials formacadamised roads. The resulting roads have proved to have better waterproofing, more resilent resultingin a smoother ride and also longer tire life. Several countries (for example, South Korea) have regulationsrequiring its use, but most do not.