I have an ‘07 GSXR and the rear tire has an obvious flat spot from (i guess) a lot of highway miles. Is there a brand or type of tire that‘s very hard in the center but still as sticky as a cheap tire on the sides for when I want to take the twisties?
Look for dual compound tyres harder in the middle softer on the sides
Search the internet [I won't do it for you] for dual compound tyres.