nope, your responsible. its a good frame and its good to learn on, but dont blame someone else for your mistakes. some people brake them, but they ride them hard and they fail beacuse of it. echos are good frames, strong but amazingly long. a freewheel will fit on your cassette hub if its got a normal freewheel thread, and it is the cheapest way to make it single speed, however if you want a well specced bike that is less likely to fail get a cassette hub and a single speed kit (i suggest hope xc/pro 2 and a gusset kit for the best price/quality ratio), but again a standard hub is fine for learning on, but you may find it breaks sooner than you may think. take it easy and keep riding Si