Motorcycle wheel wheels are predominantly made from an aluminium-alloy, but can also be made from more-exotic materials, such as magnesium content alloy or carbon fibre. The first commercial motorcycles were built like bicycles, with wire wheels as bicycles had traditionally been fitted with. The Steffey motorcycle in 1902, essentially a bicycle with a two-stroke engine attached, used wooden rims with wire spokes. This style of wheel evolved into a stouter motorcycle-specific wheel, still with spokes, up to the 1960s and beyond. In April, 1922, Borrani started production of motorcycle wheels with an aluminium rim. Although cast wheels had already been used on
Hub-center steering headstock, and the frame to be very robust adding to the bike's weight. Hub-center steering systems use an arm, or arms, on bearings to allow upward wheel deflection, meaning that there is no stiction, even under braking. Braking forces can be redirected horizontally along these arms, or tie rods, away from the vertical suspension forces, and can even be put to good use to counteract weight shift. Finally, the arms typically form some form of parallelogram which maintains steering geometry over the full range of wheel travel, allowing agility and consistency of steering that forks currently cannot get close to