To find a replacement inner tube for your Aventon ebike, you will need to know the size of the inner tube you require. The size is typically indicated on the sidewall of your bike&';s tire in a format like 700x35c or 26x2.0. The numbers indicate the tire&';s diameter and width. Once you have the size, you can search for inner tubes size or by Aventon Ebike that match those specifications.