Bike trailers, common around Davis, are used to transport children or haul cargo. Most consist of two wheels and a connecting tube which connects either to the left of the bicycle near the rear axle or to the seat post. The rear axle form is preferable. Some trailers have a single wheel. Trailers made for cargo have a flat surface, and trailers made for passengers have a foot well, a seat with some sort of padding/suspension (such as webbing), and windows so the child may look around. An alternative to a cargo trailer is a tricycle.
