hybrid bike running 700c x 40c tires that came with 700x35-43 tubes. I know tube dimensions are very forgiving but have been looking for proper tubes anyway. Found one tube that is 700x28-47 and another that is the same as the original. The 28-47 tube is a $2 cheaper, supports a larger size range of tire and weighs significantly less - 180gr vs 416gr. Am I missing something or is the cheap tire just that?