they are on thursday nights, usually starts 9 or 10pm and lasts for a while, with location changes and different spots that i have seen them at.

main one is steak and shake on 436 (semoran blvd) just north of university blvd and south of aloma. i usually stop by and check it out since i get out of work about 9:30 and its across the intersection from me. dont know alot about bikes, but the sights are nice. sometimes a few of the fuelslut cars and/or a supra or such will be out for some friendly 2 vs. 4 wheel competition.