Sucks but real cranks\spyder and you can push down HARD!
quick..gut a bike for the cranks\spyder, have a mech match the axle to the cranks.
Doubles\triples space out different =chain line to the rear.
May mean a new bb, axle is maybe 20$, new cartridge bb, 30$.
The chainrings and chains etc are replaced as you ride.
Cheap bike, ....not sure.