its normal while turning at hard.
KLIN0131_PP-2 by
Apex 86, on Flickr
you can add more tire pressure if you want to avoid running down the side wall.
more psi = less tire contact with the surface
less psi = more tire on the surface
lesser psi tend to run the sidewall down if you're corning hard. just play around with the psi and see what work for you