Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Not very happy.

I bought this bike because it was handy and portable and didn't take up much space. I got it and was initially very happy. It was light and easily stowed in what little space I have. It was easy to put together and worked well for the first two days. Then it broke. The bracket holding the magnets from the wheel gave and now I cannot pedal without extreme difficulty and a terrible grinding noise. The company that sold it gave me a full refund without any fuss. It seems like a decent product and I hope that I just got a rare bum unit.