Had you ever taken it apart and greased them? Most cheap china bikes are known for hub failure due to lack of lubrication. My Cranbrook hub died after 250 miles but it had a bearing failure after only 50. If I'd taken it apart and greased it right from the beginning it may have lasted. My new HD rear wheel has a CB-110 clone hub and it has almost 1000 miles on it without a single problem and I've serviced it twice so far. Don't bash on all coaster brakes just because your bearings failed, that could happen on any hub.