James Cracknell was the first celebrity over the finish line with a time of just over four hours and 36 minutes.
"It was brilliant," he said afterwards.
"Apart from my time, the best thing was the fact that there were thousands of people flooding into the Olympic Park, not to watch something, or see top performers, but to do something themselves.
"If there are any legacy discussions going on, that is the selling point for me - nearly 20,000 people riding out for 100 miles. I can really see this being like the London Marathon."
More top news
Police in Bangladesh have begun a raid on a restaurant where gunmen are holding 20 people hostage.
Right-wing think tank warns leaving the UK in order to remain in the EU would turn Scotland into 'Greece without the sun'.
A poll of Britain's largest trade union, seen by ITV News, indicates more than half of those surveyed think the Labour leader should quit.