Bikes thefts outside London railway stations will not be investigated if they have been locked for more than two hours.
The British Transport Police confirmed that CCTV footage will not be assessed in cases beyond this timeframe.
The force also said that robberies on trains should only be reported if the victim knows the specific carriage they were on.
Meanwhile, cases of vehicles that are stolen after being left for more than two hours will also go unsolved.
Commuters leave thousands of bicycles on racks outside the transport hubs every day, including in purpose-built hangers and parking lots.

An estimated 1.3 million daily cycle journeys were recorded by Transport for London in 2024, a figure that has increased by a quarter since 2019.
But critics have argued that the BTP’s revised guidance effectively decriminalises bike theft in the capital and will discourage people from cycling to work.
Tom Fyans, Chief Executive Officer of the London Cycling Campaign, told the BBC: "Many victims of theft in the capital just stop cycling.
“If we want to reduce car trips in London and encourage cycling we have to redouble enforcement against cycle theft."
A spokesman for the BTP said: "Whilst we know that bike thefts are upsetting, inconvenient and potentially costly, there can often be limited opportunity for investigation.

"Our experience tells us at an early stage that there are some crimes that are unlikely to ever be solved – such as those without a clear estimate of time or location for the incident or if there is a lack of CCTV or witnesses.
"The more time our officers spend reviewing CCTV footage for these offences, the less time they have available for patrolling railway stations and trains, investigating crimes which cause the most harm and providing a visible presence across the network.
"We will continue to apply a test of proportionality when determining investigation – looking at factors such as timeframes, witnesses, the availability of CCTV, the impact on the victim or whether there is a realistic prospect of a successful outcome.
"Any offence which is not investigated will still provide us with valuable intelligence, used to direct our patrols and operations."
Figures from the Metropolitan Police show that nearly 70,000 bikes were reported stolen in London between March 2021 and February 2025.