The gear wheel is one of the most purchased components by kart drivers and not just because it is subject to high wear: In fact, it allows the variation of the transmission ratio and it is therefore a must to have more than one with you every day on the track. It is often the "weak link" of the transmission (for further information read "Technique - The transmission of karts") and it is therefore necessary to pay particular attention to it, constantly checking its wear. In single-speed karts, depending on the chain it is combined with, it can have a pitch of 215 or 219, but there are also gear wheels with a pitch of 35, even if they are less used. In addition to the more traditional gear wheels made of Ergal, there are some more particular gear wheels on the market, in terms of shape, design and materials, that we are going to find out about in this article.