actually the problem is call rim "OFFSET". your new rim offset does not match the original lateral position of the rim and tire. so in your case your tire is place further outside of its normal position. then when you drive fast on uneven road/ bump, your tire will scratch your fender. next time find a suitable offset when you buy a new spanking sport rim.
Feel Cheated From This Tyre Shop., Heng Meng Auto Service Centre.