This depends on your personal preference and your go-to bike for recreational cycling. Nowadays, you can easily experiment with different stem sizes by requesting a professional bike fit from the best local bike shop available in your city. Many shops offer this service in exchange for a small fee. You can take advantage of this service to test out as many stem sizes as possible. The key to a more aggressive and aerodynamic style of cycling lies in a longer stem. A comfortable riding position with minimal stretching and less strain on your shoulders and arms can be easily achieved by installing a short stem. This will decrease the distance between the bars and the saddle.