DUBLIN's free bike scheme has surpassed the 50,000 journey mark with just a single stolen bike to spoil the celebration – and that one was found.

The scheme has been hailed a massive success with 11,000 subscribers in the six weeks since its launch, more than twice the number predicted to join up in the first two years.

Dublin City Council, which runs the service with French company JC Decaux, says it is now the most successful scheme of its kind on the continent.

The unexpected level of participation will have netted the council around €120,000 to date, even with 93% of journeys being under half an hour and thereby free of charge. And there have been few problems.

"One bike was stolen from a member while on hire," a council spokeswoman said.

"The member reported this to the gardaí and the bike was recovered damaged. Two bikes on short-term membership were not returned but were subsequently located undamaged."

The scheme, which was launched on 13 September, would have cost the council €26.5m over 15 years to run it single-handedly.

Instead, JC Decaux supplies the bikes and pays for their upkeep in exchange for permission to erect 72 metro panel advertising boards which they will operate for the next 15 years.

While the deal attracted some initial criticism when it was revealed, council officials now believe it a complete success.

"The system is aimed primarily at people who are open to the advantages of cycling who don't own their own bike," a spokeswoman said.

"The location of the stations makes it easy for people to use a Dublin bike to attend a business meeting in town, visit a city attraction or venue or simply enjoy a pleasant cycle around town.

"About 75% of journeys have been by long-term members. People can also join as three-day or 72-hour members; there have been over 3,000 of these."

There are 450 bikes at 40 docks scattered around Dublin and each bike has been specially designed to avoid theft.

With an average journey time of just 16 minutes, Dublin City Council insists it is not a money-making scheme – the first 30 minutes are free.

Bicycle use as a whole in Ireland has decreased over the years, except in the capital where, between 2002 and 2006, it increased by 6%.

The free bike scheme is also designed to benefit the 5.6 million tourists who visit Dublin each year, many of whom come from countries with similar schemes.