IT was supposed to be the summer of bike share.

And for Transportation Alternatives, the bicycle and pedestrian advocacy group, it was supposed to be a time to celebrate. A fund-raising party in Boerum Hill, Brooklyn — complete with a choreographed “Bike Ballet” — was set for Aug. 23, a date chosen early this summer and meant to occur long after the bikes had rolled out.

The party will go on. But, with Labor Day looming, the city’s bike-share program, to be the largest in the country and once promised for July, has not yet hit the streets.

On Friday morning, thousands of bikes for the program, sponsored by Citigroup and known as Citi Bike, sat in boxes in Building 293 at the Brooklyn Navy Yard.

“We’re still taking deliveries,” said a worker, who declined to be identified, rolling through the cavernous space on one of the few royal blue Citi Bikes so far assembled. Gray pieces for some of the hundreds of expected docking stations were stacked nearby. No activity could be seen at a few bike mechanic stands in one corner of the warehouse.