World record holder Usain Bolt has sent a chilling warning to his 100m rivals by insisting he can only get faster.The 21-year-old, who has also made it through to the second round of the 200m in Beijing after cruising through his first heat, believes there is much more to come.
Bolt admitted: "I've been told by people who have seen the replays I could have run 9.60sec. But my aim was just to be Olympic champion."
