New cycle-hire stations in south-west London have been officially launched by the mayor of London.
Up to 150 docking stations have been installed and 2,000 bikes provided for Wandsworth, Hammersmith and Fulham, Lambeth and Kensington and Chelsea.
More than 26 million journeys have been made on the bikes since the scheme was introduced in 2010.
The launch comes days after Barclays announced it will not be renewing its sponsorship of the scheme after 2015.
Fall in journeys
London Mayor Boris Johnson cycled over Wandsworth Bridge on one of the bikes to launch the expansion.
He said: "This expansion into great swathes of south-west London will enable even more people to hop on them."
TfL said with the expansion and the addition of 2,000 bikes, the cycle hire scheme now covers more than 100 sq km of the capital.
Leon Daniels, managing director of surface transport at TfL, said: "Expanding the scheme will encourage even more people to take to two wheels in London, whether those journeys are for work or pleasure, and we hope it will also help to deliver wider economic benefits to these areas."
Earlier this month TfL data revealed the number of journeys on cycle-hire had fallen by 200,000, almost a third, compared to a year ago.
The cost of hiring the cycles has also doubled since January.
TfL added changes were being made to the payment system for the cycle hire scheme and there are plans for new segregated routes through London.