Ed is a professional track and road bicycle racer who rides for the Rapha Condor-Sharp team. On the track his specialist discipline is the pursuit. He won the first stage of the 2005 Tour of Berlin.

He also won 2007 team pursuit world championship.

At the 2008 track championships in Manchester he was again part of the winning team pursuit squad.  

On 17 August 2008, Clancy was a member of the Olympic team pursuit squad which broke the world record in the heats with 3:55:202, beating Russia to the ride-off for silver and gold. The following day, on their way to winning the gold medal, the British team broke their own world record in 3:53:314, beating Denmark by 6.7 seconds. 

Clancy was appointed Member of the Order of the British Empire (MBE) in the 2009 New Year Honours.

In 2010 he won the gold medal in the Omnium competition at the Track Cycling World Championships. Later in the year he also won the British National Criterium Championship.