Strange how the word "Flywheel" always reminds me of a 125cc race at silverstone back in the 60's.......There I was hammering down one of the straights on my Ducati when I was overtaken by a Flywheel! Just a Flywheel! It came off a lightweight MV Agusta which was fitted with a small outside flywheel back then and this one veered off, with amazing velocity, into the centre of the track amongst the vegetation. Next lap around I spotted the MV dumped at the side with its rider frantically searching amongst the greenery. I've often wondered if he found it. Sorry I can't answer the serious query, but you know how old men's minds often veer off on a tangent when Bikes are mentioned so maybe I'll be excused this time.