Originally Posted by
mooder
Thanks for your answers. I did forgot to unscrew the stem... I managed to scrap one of the screw and I can't tighten the system enough to prevent it to move (I can't apply enough pressure on the stem). I went to LBS asking for a screw replacement but the two places I visited only carry the whole thing that is going for 30$!
This new used bike is going to cost me a lot...
It's not the bike that's costing a lot but rather your lack of attention and being careful. The odds are if you "work on" anything else you will cause more damage. A shop would have charged far less than $30 to adjust your headset, and probably could have fixed the cassette as well. You may not know when to quit but I do. I am sorry to say goodbye.