The street-safety advocates who held a die-in in Washington Square Park in July to dramatize a sharp spike in cycling fatalities have reassembled to chide Hizzoner for his recent bikelash.

Advocates from 17 street-safety organizations yesterday signed an open letter to Mayor de Blasio decrying his “recent and repeated suggestions that New York City might consider bike licensing and mandatory helmet requirements for adults.”

The letter went over well-worn ground — repeating arguments that helmet requirements depress cycling and imperil bike-share systems, that safety in numbers keeps cyclists and pedestrians safe, and that such laws are simply an opportunity for police to  target communities of color disproportionately, as they always do.

The advocates contrasted the mayor’s ill-considered remarks with his failure to implement the policies he trumpeted in July as part of his Green Wave plan to reduce cycling deaths:

“Even as the Mayor entertains suggestions that are widely rejected by injury prevention experts and have been shown by experience around the world to be counterproductive to growing bike usage, New York City bike riders still await action on key Green Wave commitments, including those for increased physical protection of bike lanes and stepped up enforcement of bike lane blocking and illegal truck routing.”

The street-safety voices asked de Blasio to move on from what they consider a “grave mistake” and instead focus on the true threat to safety: “faulty street design, reckless driving and a lack of systemic accountability for those drivers.”