A survey of scheme users also finds 4% have purchased a bike as a result of the scheme.
Mayor Johnson welcomed the fact that “more than nine million journeys have now been made using my flagship Barclays Cycle Hire scheme”.
The Mayor also said he was “very pleased that 80% of users say they think it makes a positive contribution to the capital.”
TfL’s Leon Daniels said “Thousands of people living and visiting the capital have discovered that cycling is one of the most enjoyable ways to get around London.”
The report finds that “overall satisfaction has fallen since last year’s score of 70, just over a third (35%) are satisfied.”
The number of users agreeing with the statement “Cycling is a safe way of getting about” has fallen from 37% in an earlier report, to 15%,
The document also warns that “declining scores across all measures for members suggests BCH novelty has worn off and cyclists are becoming more critical of the BCH offer.”
Availability of bikes is identified as the biggest driver of dissatisfaction and is flagged as “a priority area for improvement”.
Caroline Pidgeon, leader of the London Assembly Liberal Democrats, said: ““As the original advocates of the bike hire scheme Liberal Democrats think the cycle hire scheme is a great idea, but it has a long way to go before it becomes a genuine transport option that serves all Londoners.”
“The bike hire scheme is now 18 months old and excuses about teething problems have long passed. The Mayor should be working hard to ensure the bike hire scheme is an accessible and reliable form of transport for all Londoners.”
A TfL reported dated December 2011 reveals that 27% of members not planning to renew cited “poor availability of spaces at docking station” as their reason, with another 22% blaming “poor availability of bikes”.
TfL says it has “identified areas for improvement”.