Having the proper size inner tube for the tire is important for performance and preventing pinches. If you install a 110 inner tube in a 100 tire, the excess rubber will render it susceptible to being pinched with the tire irons. An inner tube that is too small for a given tire will have to be overinflated to make up the difference in size. Overinflation weakens the ability of the inner tube to resist damage. It is possible to run a smaller tube to save weight, but it isn’t recommended.