The Sportmax, not unlike it's younger, 2 stroke offshoot, the Ossa, only produced about 30 bhp at the arse end and even though it was an ohc 4 stroke, the combination of power to weight ratio and the pedalling talents of Herman Muller was more than enough to take the 250cc G.P title in 1955. The little NSU was also ridden with some degree of success by the likes of John Surtees and my mum . . . .
The advantages of the monocoque frame construction that embued the dustbin faired Sportmax with excellent handling characteristics were very likely remembered by the Ossa engineers and designers when formulating the plans for the Monocasco a decade later . . . . sadly, as Mr Boyle, a talent of prodidgious dimension himself, pointed out, the Ossa never met with quite the same success as it's German forebare, the NSU Sportmax . . . .
I guess the concept of the whole monocoque caper must've had some long term merits . . . . look at frame development of a majority of full on race bikes over the last thirty years, that's gotta be saying something about their potential for optimising frame functionality.
**** In the footage I've lifted from the "VintageMotorChannel" on PooTube, it shows clearly the hand formed aluminium "dustbin" fairing that was as revolutionary for it's day as the rest of the bike was, [until 'streamliner' fairings were banned . . . naturally !!!] apart from the fact they just oozed "hand fabricated" . . . . finally, it wasn't only the Sportmax that copped the pressed and welded monocoque backbone . . . . The Max, The Supermax, The Rennfox and the Rennmax, not to mention the groovy "Quickly" moped, they all sported the "onedick" spine . . . .