I purchased a chinese "Tao Tao" 110. I am pretty sure its the same as your sons. Same reasoning. He is loving it. First I noticed it had so much toe in it was twitch so I adjusted that. Then The chain was to loose and jumped off on our first trip out. Broke the cover. I got that adjusted. I have another front sprocket for tyhe front. Slow it down a little and get it to start off a little easier. So I wanted to learn from you all I can. The rear wheels? I am wanting to widen the rear and wanted to find what you learned on the rear.