The main problem is the entire bike. They are junk. They're made by Pacific, which makes cheap, crappy bikes and sells them under the guise of Mongoose, Schwinn, etc. They are trying to convince gullible consumers that the WalMart Schwinn is the exact same Schwinn available in the bike shop, only cheaper. But it's not, it's the exact same as a Pacific or Magna or some other rotten heap that you'll soon see sitting inside a Goodwill, available for twenty bucks.
Stay away, stay very far away. It's well worth the extra money to buy a real bike from a bike shop.