Bests & Worsts Reviews from Amazon

I love the idea of this bike, and I even took it to work, and it works great in short time frames (10-15 minutes) However as soon as you hit about 30 minutes it starts to clank very loud (think of a roller coaster going up its track) and i'm not able to pedal since I have it at work and don't want to disrupt anyone else. I've found a few other reviews that say the same thing as well. No i am not over the weight capacity. If this "clank" didn't happen I would love this product.