From the link you posted:
The ergonomics are relaxed and there is ample room. I’m 6-feet tall, 185 lbs., and fit nicely. It’s true. The very firm seat allowed me to position my posterior exactly where I wanted it to get me all the room I needed to the handlebars as well as the foot pegs. This is no mini-bike and there is room for just about anyone. With a seat height claimed at 29.7 inches the Grom fits most.