The pilot reported that during takeoff, the airplane’s airspeed momentarily stopped about 40 knots and then increased again, and the airplane reached its rotation speed, about 60 knots, about one-half to two-thirds down the runway. The airplane lifted off, but the pilot noticed no gain in airspeed and altitude as he began to climb out. He pitched the nose down as the stall warning horn came on, and he landed the airplane firmly on the remaining runway. The pilot could not maintain directional control following the firm landing and the airplane exited the runway striking a windsock with its right wing. The airplane sustained substantial damage to the outboard right wing. The pilot reported there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. At the time of the accident, the pilot was taking off on runway 29 with a left quartering crosswind of 10 knots that shifted to a tailwind.