Why would a 2001 Ford Focus when in motion make a 'chained wheel' type sound?

Answer 1

sounds like a C.V. joint is bad these are the axels to the front wheels. It sounds like the rear wheel bearings are going bad. There were recalls for 2001 Focus in states that use salt on their roads. Unfortunately the recall ended 12/31/03. I suggest you report it to the NHTSA. The number is 800-424-9393. They have already replaced them on hundreds of thousands of 2001 Focus'. When you get it repaired save your receipt, Ford will reimburse you if they reinstate the recall.