A related question is when do you raise the gear after liftoff?
I will not raise the gear before positive rate and Vy, unless it's a Vx critical departure, which would be pushing things anyway! That said, I will generally wait until I have overflown whatever suitable wheels down runway over run, or clear area ahead could be used for an EFATO forced landing.
Decades back I was being checked out in a rental Piper Arrow IV in Florida. It was a hot day, and the instructor directed me into a runway a little shorter than I would have preferred. No problem getting in, but getting out was not a perfect scenario - there was lots of city off the departure end of the runway. I informed the instructor that because I felt this would be a more "maximum performance" departure, I would "lock off" the Piper Arrow automatic gear extension system, which I also knew (from previous embarrassing event) would prevent the retraction of the gear after an up selection, if the magic airspeed had not been reached. I wanted the gear to retract when I wanted it up, to make the most of my departure. The instructor (whom I'm not sure had ever flown an Arrow) a: did not understand what I was talking about, and b: then, upon my explanation, objected to my deliberately bypassing a safety system. I replied that he could allow me to do it and pass my ride, allow me to do it, and fail my ride, or take the airplane home without me aboard. I locked off the auto gear extension, departed just fine, and passed my ride. I wondered if the instructor went to review the POH for the Arrow IV that evening!