* Bradley Wiggins' Tour victory boosts British hopes
* Syrian athletes arrive, freed Libyan chief en route
* Transport woes temper celebratory mood
LONDON, July 23 (Reuters) - Britain basked in the glory of Bradley Wiggins' historic triumph in cycling's Tour de France on Monday and looked ahead with relish to more sporting success at the Olympics, boosting the nation's hopes after a troubled buildup to the 2012 Games.
Olympic officials announced that Syria's athletes had arrived to take part in the London Games, ending uncertainty over whether the nation under increasing international pressure for a bloody civil conflict would be officially represented.
In a reminder of logistical challenges facing London as it prepared to stage the greatest show on earth, commuters using the ageing metro system reported major delays and transport union RMT called for fresh, albeit limited, industrial action.
And Olympic chief Jacques Rogge reassured 11 million ticket-holders that the July 27-Aug. 12 Games would be safe, after the failure of private security firm G4S to provide enough guards provoked heated debate among politicians and in European media.
Thousands of extra soldiers were recruited to fill the gap at an event where security concerns are particularly high - 2012 is the 40th anniversary of the 1972 Munich attack by Palestinian militants that killed 11 Israeli Olympic team members.
Rogge paid tribute to the victims at a symbolic ceremony at the Athletes Village on Monday, although he has turned down repeated calls to mark the anniversary at the opening event.
"We're very confident that security will be very, very good," Rogge told BBC, when asked about the G4S scandal.
"I believe we have to move on. The problem has been identified, the problem has been addressed in a good way," added the president of the International Olympic Committee.
Britain was rocked by suicide attacks on London's transport system that killed 52 people in July 2005, the day after the city was awarded the 2012 Games.
A huge security operation, complete with rooftop missiles and costing around one billion pounds, has been staged, but the fact that security levels have not been raised points to confidence the Games are not being specifically targeted.
More than 16,000 athletes from 204 nations will contest medals across Britain at the Games, bringing the thrill of victory and despair of defeat to millions of onlookers and billions more watching on screens around the world.
Household names like Jamaican sprinter Usain Bolt and U.S. swimmer Michael Phelps will seek to steal the limelight with more titles and world records, although question marks over the runner's fitness, specifically a tight hamstring, linger.
More obscure but no less dramatic is the promised attendance of Libyan Olympic Committee President Nabil Elalem, who will be in London after being freed on Sunday a week after being seized by gunmen in Tripoli.
Syria will be represented, although Pere Miro, in charge of relations with national Olympic committees, told Reuters that some officials had decided not to come, avoiding potential embarrassment given the condemnation of the tactics being used by President Bashar al-Assad to try to halt the uprising.
The signs on Monday were that, after a negative buildup to the Olympics by Britain's notoriously caustic media, the feel-good factor had arrived at last.
Even the weather obliged - the sprawling Olympic Park in a once poor quarter of east London where many medals will be fought for across myriad venues basked in uninterrupted sunshine following an unseasonably wet June and early July.
Newspaper front pages and radio and television programmes were full of Wiggins' Tour de France win, the first British victory in what is billed as the world's most prestigious race.
And with fellow Briton Mark Cavendish sprinting to the stage win along the Champs Elysees in Paris, attention turned to their chances of winning home cycling golds at the Games.
Cavendish, who will contest one of the first medal events in London on Saturday, was in bullish mood.
"I'm very ready for the Olympics now," he said after his stage win in Paris. "We're going to have an incredibly strong team and we're not just going to the Games to see how it goes."
In another nod to British success on two wheels, four-time Olympic track cycling gold medallist Chris Hoy will carry the British flag at the opening athletes' parade.
On Monday, the Olympic torch made its way around the capital and completes its journey on Friday evening when the cauldron is lit, symbolising the start to the Games at a ceremony expected to be a more intimate affair than the 2008 Beijing extravaganza.
That promises to be a "wow moment", British Olympic Association chief executive Andy Hunt said at the weekend, with the identity of the privileged role of lighter and even the location of the cauldron still a closely-guarded secret.
In the afternoon the torch goes to Wimbledon where Andy Murray, this year's men's runner-up at the grand slam event, will carry it on to Centre Court and hand it to former women's Olympic tennis champion Venus Williams of the United States.
With four days to go until the opening ceremony, transport disruptions across London were a reminder that there were still significant threats to a smooth run-in.
Severe delays hit three of the main rail links to the Olympic Park on Monday morning and labour union RMT announced industrial action by staff in some parts of the city's old and often creaking transport system to coincide with the Games.
Problems on the underground Central and Jubilee Lines were compounded by delays on a key overground link, and passengers rolled their eyes in disbelief at announcements explaining the reasons for their woes.
"This is going to be brilliant for the Olympics," said one passenger on the crowded but at least functioning Northern Line, to laughter from travellers packed into carriages like sardines.
Olympics minister Hugh Robertson admitted that transport in London during the Games was a challenge, but added:
"Can I absolutely guarantee sitting here today that it will be faultless? No, because this is a huge, huge city. Many millions of people are going to work every day and to do other things. Can I assure you that we think we've done everything possible to make it work? Yes, I can." (Additional reporting by Alan Baldwin, Avril Ormsby, Michael Holden and Sam Speed in London, Julien Pretot in Paris; writing by Mike Collett-White, editing by Peter Millership)