oooh dem crank grinds. one of my favorites!! i learned it surprisingly easily missing an icepick on a curved rail and just landed on it and on that last bit just did it. and now i just do em. Idk why but i honestly enjoy grinding the crank arm instead of my pegs. just pull your front wheel over and hop of course and land on the arm/ part of the pedal to lock it in and try to stop your legs from moving too much so you dont hit your sprocket. have fun!!!
References: OneGuyIlluminatiEye, robinson79, Brian Griffin, The Horror Contact, StoreBoughtChild, C_Johnsonbmx, dkTechEthan, etc.