News that Barclays will stop sponsoring London's bike hire scheme is yet another bump on the road in what has been a bad year for the so-called "Boris Bikes".

Fewer people are using them, they are bleeding cash, and cycling in London is surrounded by a fierce debate amid a number of fatalities on the road - including the first on a Boris Bike.

Barclays said it would not be opting for an originally proposed three year extension of its sponsorship deal when the current contract expires in 2015. This is despite London's mayor Boris Johnson declaring in 2011 that the relationship would last until 2018 and bring in an extra £50m.

The investment bank cited "commercial" reasons. It is reviewing its sponsorships in the wake of several multi-million pound regulatory fines for past bad behaviour, such as Libor fixing.

Transport for London (TfL), the authority which oversees the bikes, tried to play down the impact of the announcement.

"Cycle Hire will become part of a much wider and larger cycling sponsorship offer encompassing Cycle Hire and the major new commitments made in the Mayor's Cycling Vision - new flagship segregated routes through the heart of London, new Quietway backstreet routes, along with cycle training and potentially other forms of active travel," said Graeme Craig, TfL's director of commercial development.

"The Cycle Hire scheme will be fully integrated with our plans for pay-as-you-go contactless card payments, making it a fully joined up part of the transport system.

"In recognition of the growing demand for cycling expenditure, TfL is to seek new commercial partners to add significant sponsorship income to the £913m already devoted to cycling."

He added: "There will be no reduction in public funds spent on the cycling programme, which have been entirely protected from the cuts in the Comprehensive Spending Review and Autumn Statement."

A spokesman for TfL would not say if any potential commercial partners had been highlighted or approached, or how long the transport body had known Barclays was to end its sponsorship.

Cycle Hire figures show plunging usage in the wake of higher fees for users. The number of hires tumbled almost 30% in November when compared with a year before, from 726,893 to 514,146.

Johnson doubled the cost of hiring the cycles from January 2013, precipitating the drop in usage from 2012's peak as the city hosted the Olympic and Paralympic Games.

Customer dissatisfaction grew after the price hike. An internal TfL report featuring an opinion poll, released to the MayorWatch website under freedom of information legislation, found 40% of users thought the bikes were too expensive. It was the biggest reason people gave for being unhappy with the scheme.

"There has been a significant increase in those saying they will not renew their membership when it runs out, mainly due to cost reasons and availability of bicycles and docking points," says the report.

It is also heavily subsidised by taxpayers. The whole scheme's construction and operation, which is extending into new boroughs, will cost £225m in its first six years. The shortfall will be picked up by TfL and local public authorities, such as councils, who are already suffering under the strain of government austerity cuts.

In August, the scheme was hit by 48 hours of strike action as workers signed up to the RMT union walked out over pay and working conditions. The RMT accused bosses of "bullying".

Just a month before, a 20-year-old woman became the first cyclist to die while using a Boris Bike. She was involved in a fatal collision with a lorry by Aldgate East tube station near the City.

Cycling campaigners have long warned of the dangers of London's roads, but the fight to make using a bike safer in the capital has intensified after a number of high-profile deaths. There have been 14 cycling-related deaths in London across 2013.

It appeared that in the context of waning popularity and fears over cycling the capital, as well as its own burden of regulatory fines, Barclays no longer had the palette for Cycle Hire sponsorship.