London's colorful mayor, Boris Johnson, has made it a priority to get more of his constituents on two wheels. But a series of deaths on the city's roads have shaken cyclists and noncyclists alike.
The number of Londoners cycling to work has more than doubled in the past decade. On some roads, cyclists now make up more than half the rush hour traffic.
And for years, Johnson has been among them. Many think the London mayor has his eye on Prime Minister David Cameron's job.
The libertarian-leaning Johnson is rarely seen in a helmet. He won't be bullied into wearing one, he says.
But it's his public, not his personal, safety choices that have him in the firing line: Fourteen London cyclists have been killed so far this year. That's a higher casualty count than that of the British military in Afghanistan.
The city's cycling commissioner, Andrew Gilligan, calls the latest deaths a statistical blip, though a tragic one.
"It's difficult to see any pattern: The number of fatalities is on course to be roughly what it was last year," he says.
But at London's Waterloo station, Tom Bogdanovich of the London Cycling Campaign says there is a pattern to the deaths.
"They do happen on busy roads, and they do happen at junctions," he says. "And they do — very often — happen between very large vehicles and vulnerable road users like cyclists and pedestrians."
As he talks, trucks and buses hurtle by the station's bike stands, which can hold 300 bicycles.
Several of the latest deaths happened on the mayor's so-called cycle superhighways — blue-painted lanes on busy streets where cyclists theoretically have priority.
And all the accidents involved heavy goods vehicles — HGVs — the trucks that trundle through the capital 24 hours a day.
That's led to calls for HGVs to be banned during commuting hours, the way they are in Paris, and for barriers to protect bike lanes.
The London mayor says his team is constantly reviewing safety.
"Do not underestimate our ambition, our determination to make this a truly fantastic place to be a cyclist," Johnson said.
But he also infuriated many cyclists by saying they should be more careful.
When bike blogger Mark Ames suggested a protest ride through some of the capital's worst accident hot spots, hundreds of his fellow cyclists turned up.
"People in London are furious," he says. "This is a leadership crisis for Boris Johnson: He's been encouraging people to cycle in London for five years now. In that time, 80 people have been killed."
There's pragmatism behind the mayor's drive to encourage bicycle use: It's the fastest, cheapest way to take pressure off London's straining public transportation system.
But Johnson has been encouraging vehicle use, too.
As a contrarian, conservative, car-loving columnist, he once wrote that the natural response to a speed bump is an SUV. And as mayor, he's reduced the size of the congestion zone, the area in central London that drivers have to pay to enter.
He says it's all an effort to make it easier for goods to get to market and for Londoners to get to work to keep the capital's economy competitive.
Back at Waterloo station, management consultant Rupert Angel unlocks his mountain bike. He says he always keeps to quiet back streets; that's why the recent fatalities have left him unfazed.
"Because there's a lot of people cycling and some people will get knocked off," he says. "And I don't cycle on roads where people are going too fast."
This week, the mayor announced that 2,000 additional police will be on the streets, enforcing all traffic laws. And he said he wants to crack down on cyclists wearing headphones.