Thanks for sharing.
Dont know about record,,,but yes, have not heard of any larger capacity single cyl bike than the BISON.
NSU was another amazing company from Germany...along with Imme...Munch...etc.
They all inovated ideas that are realised now...or will be, 20 yrs ahead of today!
Your comment/post was quite amusing!
BTW this particular bike was NOT for the market. FYI they had a whole other line up from 25cc ....
The 'bike' in the photo are one-of masterpieces...things that test the limits of physics and mechanics.