London bike thefts rise by a third in five years
More than 26,000 bicycles were reported stolen to the Metropolitan Police last year, up a third on five years ago, BBC London has learned.
Arrests for thefts and numbers of bikes recovered by the police are also down on last year.
Cycle campaign groups say the figures only tell part of the picture as only one-in-four people report stolen bicycles to police.
The police say owners need to take more responsibility for their bikes.
Cyclist Rob Patterson has had two bikes stolen from the racks at Liverpool Street Station.
On the second occasion he told the police he had seen his bike on an online trading website, but the police did not return his call.
"It seems like they're resigned to the fact that bikes are going to get stolen," he said.
"I effectively did some detective work for them, and I was cast-iron sure I'd caught them a bike thief. They just weren't interested. It makes me really angry to be honest."
A Freedom of Information request by the BBC showed that despite more thefts being reported to the police, in the past 12 months arrests for bike thefts have fallen by 10% and the number of bikes recovered by the force is down for the second consecutive year.
Just under 1,000 bikes - less than 4% - were tracked down by Scotland Yard in the last financial year.
'Get bikes back'
Mike Cavenett of the London Cycling Campaign group said the figures only gave part of the picture.
"Only about one in four bikes in London is reported stolen. That means there could be around 100,000 bikes stolen every year, which is clearly a huge problem.
"The government's spending a lot of money encouraging people to ride their bike and when their bike is stolen about two-thirds of them don't get back on a bike," he said.
But the Met's Cycle Task Force, set up in 2010, says owners can do more to safeguard their bikes.
Sgt Paul Davey said: "If everyone had their bike registered and we had a contact detail which is linked to a security marking which is linked to the frame number on a bike - they're both unique - we could get bikes back to people all the time.
"We could raise that number from 4% up to 100%."