Complex sentence: At the time of Ripp's ownership, its chief rivals were Demon Tweeks and Grand Prix Racewear, following its sale, Halford discarded its motorsport retail side of its business and concentrated in purely car modifications, largely the boy racer market.
Split into simpler sentences: At the time of Ripp's ownership, its chief rivals were Demon Tweeks and Grand Prix Racewear. Following the sale of Ripspeed, Halfords discarded its motorsport retail side of its business and concentrated in purely car modifications, largely the boy racer market.