Display MoreSo you have 4 wheels?
Two driven from the hoverboard and two passive caster wheels?
The caster wheels are not fixed?
Forward means the caster wheels are in front or back?
Questions over questions, you really should provide much more information for a chance to get help.
You can use something like that:
Do you think that type of caster wheel could handle the weight of a person? Like 60 - 80 kgs? (132 - 176 lbs)