The solution to the German fan belt problem is wrong.
First, assume that a belt wears thin until it fails. Let"s take for an example a belt which fails at 100 hours when it has worn to 50% of its original thickness. The belt is formed as a moebius loop and a point on one side is marked “A”. After it has run 100 hours the point marked “A” will be found to have worn down only 25%. Unfortunately, the belt now has only one side “A” so the “other” side of point “A” will have worn down 25% also. The belt, worn 50% total, will fail.