Tribeca’s fitness boom continues…. BKPilates, which has outposts in Sheepshead Bay and the Flatiron District, will soft-open a Tribeca studio next week. It’s on the second floor of 406 Broadway (Canal/Walker), and judging from the schedule, most classes involve Reformer machines. BKPilates is running a pre-opening special (“while supplies last”): 50% off a ten-pack of classes at the Tribeca location.