Yeah,
A good article. The velocity change in a uni is not commonly known, but as they say in the article, it is very important to get the phasing correct so both joints are increasing and decreasing speed at the same rate, at the same time. I have never thought of it in terms of flywheel blts but you could be onto something here .


To remove a lot of the angular change, some luxury saloons (300C ) and 4WD'S use a double Cardan joint (double cojoined iniversals) at each end of the shaft. This halves the joint angle experenced by each joint. These are a smoother tougher drive shaft but are very expensive to make.