A bicycle stand, also commonly called a bike rack, is a device to which bicycles may be securely attached. Toronto (təˈrɒntoʊ colloquially pronounced or) is the largest city in Canada and is the provincial capital of Ontario It may be free standing or securely attached to the ground or some stationary object such as a building.
Early models tend to offer a means of securing one wheel: these can be a grooved piece of concrete in the ground, a forked piece of metal into which a wheel of the bicycle is pushed, or a horizontal ladder providing positions for the front wheel of many bicycles. Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag These are not very effective, since a thief need only detach the wheel in question from the bicycle to free the rest of the bicycle. They also do not offer much support, and a row of bicycles in this type of stand are susceptible to all being toppled in a domino effect. This article is about chain reactions. For the political theory, see Domino Theory. These types of stand are known as "wheel benders" among cyclists.
A modern version is known as the "Sheffield rack" or "Sheffield stand", after Sheffield in England where these were pioneered. Sheffield ( is a city and Metropolitan borough in South Yorkshire, England These consist of a thick metal bar shaped like a square arch. The top part is about level with the top bar of the bicycle frame, and thus supports the bicycle and allows the frame to be secured. High-quality versions feature a second, lower horizontal bar to support smaller bikes (this version is also known as “A stand”), and are coated to reduce their surface hardness and thus reduce the risk that the paint of attached bikes gets scratched. Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force
Since 1984 the City of Toronto has installed post and ring bicycle racks consisting of a steel post topped by a cast aluminium ring. Toronto (təˈrɒntoʊ colloquially pronounced or) is the largest city in Canada and is the provincial capital of Ontario  In August of 2006, it became publicly known that these stands could be defeated by prying the ring off with a two-by-four 
In Amsterdam two-tiered bicycle stands are ubiquitous. The bicycles can be parked in a smaller area as the handle bars (the widest part of the bicycle) of every other bicycle is at a different height (either high or low). These racks are made of steel and have a large bar that make it easy to lock the frame to to the rack. Most dutch bicycles have a rear wheel lock, so the rear wheel does not need to be locked.