Fuel for the fire.
My grandson has one of those *mart bikes that just
happened to have the crankset that allows for the
cranks to be changed (square press fit bracket).
Due to crummy assembly his left crank fell off
and the nut was lost. He now can't ride until
his mother finds a proper metric(?) nut to
re-attach the crank. At least the guys at an
LBS know how to torque things when they assemble
a bike.
Bill