The latest in the list of these motorcycles is the naked Aprilia Tuono 457 ... There's a new Tuono V4 Factory version for you ...

The Tuono V4 Factory continues to push the boundaries and forge ahead of rivals, new and old, that every year try to knock it off the top podium in the class invented by Aprilia.

which is a major reason why the hillclimb no longer accepts motorcycles (and therefore why Aprilia will forever hold the record time of 9:44.963 set by Rennie Scaysbrook on that Tuono V4 1100 ...