The time has come to replace my rear tire. It is the Dunlop sportmax that comes stock on the F4. It has that flat groove right down the middle that you get from too much straight line driving(Just learned how fun knee dragging corners was this year!!! ) As cool as it is to take some deep corners, the majority of my riding is straight highways. Does anyone have any suggestions of a tire that is better suited for normal upright riding? Is there such a thing? Could there be a tire with a reinforced middle tread? I would appreciate any help.