You can really see how strong chimps are if you look at one that doesn’t have any hair. Here’s a Google image search on it: http://www.google.com/images?client=firefox&rls=en&q=hairless%20chimpanzee
Some good examples:
http://img132.imageshack.us/img132/2821/baldchimp5bk6.jpg
(This is one of the skinnier ones, but it’s interesting because it looks so much like a human.)
I wonder how a chimp would compare in strength to a world-class bodybuilder. Of course, in a fight the chimp as the advantage if its teeth.