DID ERV7 520 Road Racing Chain -120 link

D.I.D's High Performance X-Ring® for Road Racing (120 links)

It's what Valentino Rossi uses on his 260hp Yamaha M1 MotoGP bike - so it's probably good enough for you too :)  

 Strength, Style, and Performance all come together with DID's most popular performance road racing chain.  With a tensile strength of 8660lbs, it'll withstand the rigors of road racing AND street use.  The Gold color makes it stand out from the crowd, and the performance in the 520 series is so good, you can replace your heavy, stock 525 or even 530 chain and shed some weight to reduce rotational mass in the drivetrain.

Half the Power Loss (Compared with Normal O-Ring)
D.I.D’s PATENTED X-Ring construction reduces friction by twisting between the side plates instead of being squashed. Normal O-Rings and other makers’ modified O-Rings have squashed points that increase friction. The twisting action of the X-Ring disperses the pressure and minimizes power loss.
X-Ring is a U.S.A. Registered Trademark of D.I.D; Daido Kogyo Co. Ltd. Japan

1.5 to 2 TImes Longer Wear Resistance (Compared with Normal O-Ring)
The X-Ring’s four contact points greatly increase its sealing performance. This keeps the dirt out and the lubrication in much better than any other O-Ring. X-Rings have the greatest wear resistance of any other type of O-Ring or Non-O-Ring chain.