My daughter rides a SUNL-70 in the firmer packed sand around camp and doesn't have any issues (with stock tires no less). Of course in the normal softer dunes the thing is a "No-Go". After years to Glamis, Dumont and Pismo I've found that anything under a 350 (2 stroke) or 400 (4 stroke) is a waste of time. 250's will do ok around camp for a small 'adult' but don't cut the mustard in the big stuff. As for kids, I don't think there is anything on the market that would be safe for them to ride on a family romp through the dunes. I'd say a 110cc or 150cc for around camp would be good for a decent sized 'pre-teen'. Like others have mentioned and I have witnessed, there is nothing worse than helping a 8 year old with multiple broken bones that just had a 250cc Quad roll over on him until the paramedics show up, it's a buzz killer.

 

thanks airborne1