This important component is often regarded as the ‘face’ of the motorbike, and its size, shape and color are often considered one of the main determining factors of your first impression of a bike’s design. As you may already know, the main function of the gas tank is simply to hold petrol. However, did you know that the gas tank also provides a secure area for your knees to grip while riding the motorbike, acting as a very important point of contact between you and the bike.