At the Cancun meeting of the world trade talks in September 2003, a powerful new grouping of developing countries emerged. Led by rapidly growing countries and major exporters like Brazil, China, India, and South Africa, this group has been powerful enough to challenge the EU and the US in trade negotiations.
If the situation is really bad it can even be caused by the rod itself contacting the crankshaft journal (where the bearing has become out of place). The most common cause of rod knock is due to a spun bearing (bearing itself actually spins in the end of the rod so it becomes out of position).
There are a number of reasons why pipes knock. One of them is excessive pressure. Anything over 60 psi is enough to cause pipe knock. In addition faucets that have cartridges often cause pipe knock, because they stop the water too fast. When you get water flowing in one direction and you shut it off quickly, all the forward motion is has no place to go. It is absorbed in the piping with banging.