They are correct. It was designed to shake by using the single pin crankshaft (both connecting rods connect on same journal) which is what HD has been doing for ages. It creates the shake and the potato-potato sound unique to this engine design. The ACE 1100 Tourer had the double pin crank, more performance, less shake, a better engine frankly but not a HD clone which was Hondas intent with the ACE.