The one I had was a Go-Ped sport, hard tires about 6" tall. It would go over cracks decently enough... but man... the vibrations youd get through your hands and your feet were absolute murder lol. Half from the hard tires, half I'm sure from the 2 stroke motor.
I juiced mine right up naturally

. I got it as a 23cc with a restrictive airbox and box muffler.. bought a bigger top end and a stuffed crank with +2mm stroke bringing it to 30.5cc, bigger carb with a velocity stack, and a super obnoxious fatty tuned pipe for it..
After i did all that it had enough mustard where a good crack of the throttle would pull the front wheel off the ground with all my 200+ lbs on it. I didn't initially realize this.. so I got sent off the back of it in the middle of traffic one day and skun my knee all to hell lol. It was hard playing that off like I wasn't in the worlds largest amount of pain

mostly to the ego.