Gay ready to challenge Bolt

American sprinter tyson gay is promising fireworks at this summer's london olympics, where he's expected to renew rivalry with jamaica's reigning olympic double sprint champion Usain Bolt.
The second fastest man of all times with 9.69, gay, says he's returning to his best after an injury wrecked 2011 season, which him ruled out of the Daegu world championships.
Gay, will be aiming to make his first olympic final, after disappointing four years ago in beijing 2008.