The union is to ballot members employed by Serco, the private sector company which manages the scheme for Transport for London, for both strike action and action short of a strike in a row over pay and conditions.
Grievances include a pay cap of 2% pay increase for 2013, changes to shift patterns and claims of “continuous bullying and harassment of members”.
TfL has previously expressed unhappiness with Serco’s performance.
Announcing plans to ballot members, RMT General Secretary Bob Crow said: “Despite warnings that the so-called “Boris Bikes” are facing severe docking and capacity problems, the staff running the London cycle hire scheme are facing a bullying management who are imposing outrageous changes to conditions of service while denying our members a fair pay increase for a massively increasing workload.
“RMT will not stand aside and watch this group of key transport staff get kicked from pillar to post. The London Cycle Hire Scheme is much more than a vanity project and a publicity stunt for the London Mayor, it is now a valuable part of our transport system and the staff should be valued as such.”