[40580]

according to apriliaforum.com they come with an extra 15t under the front seat. This is from the forums administrator AF1 Racing.

 

[vermicious]

Ah, thanks!

 

[4940]

In this month’s Cycle World they reported that the Tuono comes stock with a 16 tooth front sprocket (to meet DOT noise standards) but all bikes were shipped with a "spare" 15 tooth sprocket which provides the kind of acceleration that the bike was meant to have.