I have just had a conversation with a guy from Michelin and he has told me the mark is a antistatic strip see email: In summary no need to worry "Thank you for your e-mail. From what you describe they sound like the anti-static strips that are in the tyre tread. You can continue to run the bike at normal speeds and these strips will 'disappear' within a few hundred miles .They have no detrimental effects on the performance of the tyres. All Pilot Power/Sport/Road tyres have this strip but only a few riders notice it!" I have attached a 'simple' diagram as explanation. Pilot Power A circumferential groove approx. 2 to 3mm wide and 3 to 4mm deep Two Wheel Department, Michelin Tyre Public Limited Company |