You will find them at the rear of the bike, since this is the wheel that will receive the most shocks in bmx. The ideal is to have double wall rims in front and in the back. And of course, remember to maintain the spoke tension often in order to limit the risk of warping. It is then preferable to choose a high level bike, which will use more resistant materials. Note that the level of a rider evolves with time, and that logically his bike will have to evolve in the same direction. On the other hand, following this logic, it is strongly discouraged for an expert to choose a bike for a beginner rider. Especially when it comes to the quality of the bike’s equipment and materials. Generally, each data sheet is marked ”Recommended for” to indicate whether the bike is for a beginner, intermediate, pro or expert rider. They are a great way to exercise and are also very necessary for transportation.