Probably a dumb-ass question here .... .... I've had the bike twenty-odd years and never given this much thought . The drawing shows the connection of silencers ( arrowed ) and exhaust pipes through a cross-piece , which is a fixed part of the exhaust from the horizontal cylinder .... sorry it's so fuzzy I'm guessing that there is some benefit to have the exhaust gases from both cylinders mixing . Better engine breathing , back pressure or vacuum .... something like that ? Is this arrangement the same for most Ducati twins ? -