Setting off from Notting Hill, the Prime Minister arrived in Stratford a little over an hour later in the company of thousands of pedalling East End schoolchildren. In a media briefing later, the No 10 press secretary said this was another example of "one-nation Toryism in a modern setting", proving "it is morning in Britain again".
Welcome to Cameron's Britain. It's a place that Gordon Brown wants us never to visit - but what would it really be like, this strange new terrain?
The biggest difference, says his former tutor, would be in the way public services are delivered. "David Cameron's Britain would have a smaller state and one in which targets play much less of a part," says Professor Vernon Bogdanor, vice-principal of Brasenose College, Oxford. "There would be notably more diversity and choice." Cameron would also be far more of a libertarian than previous Tory PMs.
But for all the candidate's talk of "modern compassionate Conservatism", Cameron's Britain would look a lot like the 1950s, for grammar and grant-maintained schools would spring up again. He wants schools to be free to introduce selection and impose discipline.
He has also come close to calling for a return to national service, stressing it would be a non-military "three-month school-leaver programme". Mindful of his own rarefied upbringing, perhaps, he believes it would mix youths from different backgrounds while promoting civic virtue.
His insistence that existing, as well as aspirant, British citizens be "encouraged" to learn English is another echo of the past. Then there is his claim that the UK could leave the European Convention on Human Rights, and his attitude to the European Union. So far he has also failed to distance himself from the Tories' much-mocked "asylum island" policy of processing applications offshore - possibly because he helped to write the manifesto that included it.
Changes to Britain's demography and global economic trends will, however, have a greater effect on the country's future than any change from a centre-left to a centre-right government, say futurologists.
Peter Thomson, director of the Future Work Forum at the Henley Management Centre, says a future Tory PM would have to find a way of embracing immigration - or threaten the UK's economic future.
But Thomson says that David Cameron has shown that he understands the consequences of one other key aspect of Britain's indigenous labour shortage - far greater demand for "work-life balance". Far from being old-fashioned, his policies on tax breaks for married couples, as well as his rhetoric on supporting families, are actually in tune with the aspirations of many.
"There will be a growing respectability - even cachet - about being able to afford to have at least one parent stay at home with the children."
Cameron's own personal background - he is father to a four-year-old son who needs 24-hour care - means he speaks with natural authority on the subject of balancing career and family.
"The quality of life matters as well as the quantity of money," he told the Conservative conference in Blackpool, in a phrase that resonated far beyond and would have bombed in the mouth of any other frontline Tory. The balance between work and home is no longer exclusively Labour territory - and Brown needs to watch that he doesn't concede other ground.
Cameron is keen on devolving power to local communities. His Britain would see almost every town and city run by directly elected mayors and policed under the control of an elected commissioner.
Thomson even detects a change in attitudes that means Cameron's background may be less of a problem than his opponents believe. "There is a growing sense that we want to look up to figures in positions of authority again. We want a return to that culture of respect. And if Cameron can maintain a sense that he is above the sleaziness of normal politicians then his background could actually help."
Professor Bogdanor agrees that Cameron's class will play less of a role than it did in the 1990 contest, when Douglas Hurd, the last Old Etonian challenger, lost to John Major, the man from Brixton. In any case, "Dave" - the hard-drinking, tennis-playing student who "had a life" - was far from a typical toff, says his tutor.
Sir Eric Anderson, Cameron's headmaster at Eton (and, coincidentally, Tony Blair's house master at Fettes), agrees that his former house captain was a "very nice boy", but declines to speculate on what the country would be like under his command - for now: "Maybe when he's prime minister we'll talk again."
And maybe when Cameron is PM he won't be the only Old Etonian at the head of the nation. The future King William is seeking to project the same "regular guy" image as the would-be Tory leader, a curious mixture of the old-fashioned and modern. If the monarchy can reinvent itself, why not the Tory party?
FROM BLAIR TO CAMERON IN EIGHT SIMPLE STEPS
1 December 2005 Cameron wins ballot of Tory members and is elected leader
2 February 2006 Tories lead in the polls for the first time in five years
3 May 2007 Tony Blair stands down 10 years after Labour took power
4 June 2007 Gordon Brown becomes PM
5 May 2010 Shock election victory gives Cameron narrow majority
6 August 2010 Cameron's first 100 days see quangos axed and tax breaks for stay-at-home parents
7 July 2011 Cameron's ruthless reshuffle promotes "new Tories" to top positions
8 August 2012 Cycles to Stratford for opening of London Olympics, saying, "It's morning in Britain again!"Reuse content