I don’t know if anyone knows the meaning of that phrase !!
I have seen an entire family on a motor cycle: Dad driving (& the only one wearing a helmet), mum holding baby in the back (riding side-saddle) & older child in the front helping dad to steer.
I have seen a bike loaded up at the back with a child sitting on the load, clinging to daddy (who is, of course, wearing a helmet).
I have seen guys on push bikes with three big gas cylinders in the back (two by the side & one over the back): didn’t want to think about whether they were full or not.