Budapest George Ezra
Staff who help operate the cycle hire scheme, known as Boris Bikes, are to be balloted for strikes in a row over hours and payment for working during the Olympics.
The RMT union said its members had not been offered any extra pay for being on duty during the Games, and were facing lots of changes to working hours and shift patterns.
The union has already secured one-off payments of £850 for tube and train drivers.
General secretary Bob Crow said: "Despite an increasing workload this summer as we head towards the Olympics 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 any additional reward for the pressure of the Games.
"RMT will not stand aside and watch this group of key transport staff get kicked from pillar to post."