If you often load up your bike with shopping or luggage or carry a child on the back, you'll want only the most stable bike stand. In this case, it's better to have two legs than one. A stable two-legged stand for mounting behind the bottom bracket is should be your first choice. As with conventional side stands, you should also make it's the right size: this is usually indicated in the item description. Unlike one-legged versions, the right length is not only important for stability but when operating: a little effort is required to push the stand down towards the ground and under the bicycle.