I was browsing ebay as you do, and come across this, What is so special about it ? Surely it's as good/worse than a c16/c21 ? anyone got any idea ? http://www.ebay.co.uk/itm/PIAGGIO-Z...cycle_Parts&hash=item415b730498#ht_2989wt_702
Because it's a full on race exhaust. Bit of history here... Back when Yasuni's were first about they were only made for minarelli engines and not piaggio's. The Hebo Manston pipe was one of the best exhausts made for highly tuned piaggio engines along with the polini evo exhaust and the Malossi MHR team exhaust. As soon as Yasuni started making their exhausts for piaggio then no one bothered with the hebo pipe any more. It's up there with the C20/C21.
Ooooh right I see Looks like a nice pipe, can't really afford it though and would be very stupid on a sport kit lol.