Complex sentence: In 1998, Aprilia released an all new look for the RS250, also referred to as RS250GP1 to celebrate Aprilia's victory in the 250 cc GP racing class.
Split into simpler sentences: In 1998, Aprilia released an all new look for the RS250. It's also referred to as RS250GP1 to celebrate Aprilia's victory in the 250 cc GP racing class.