A neighbor child had one of these. It would not shift correctly because it was not designed to. The rear end wobbled about so that the chain line would change and cause phantom shifts. These are perhaps, singularly, the worst BSO in existence. And mind you, I said the worse BSO and mind you that "it" in no way qualifies as a bicycle. This is a waste of time. There are much better options for far less money. Some people will go to any expense to save a dollar. Your friend is not serious about a bicycle for transport or sport, whatever the case may be, and you are wasting your cycling mechanic-ing time on him. If he/she were serious, they would invest in a bicycle that would not waste your efforts and good intentions upon.