My friend bought an X-mart Diamondback and man was it a piece, the crank arms actually fell off, bars bent, rims tacoed, seat/seat post bent, and the list goes on. But do I really need to continue? I had a X-mart CCM awhile back and I destroyed the rear derailer within the first 2 weeks I had it, it became a manual changer. Some how I still have it and I use it as a makeshift trials bike (it's good for doing manuals )