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
Tire Wear bars (or wear indicators) are raised features located at the bottom of the tread grooves that indicate the tire has reached its wear limit. When the tread lugs are worn to the point that the wear bars connect across the lugs, the tires are fully worn and should be taken out of service. Most wear bars indicate a remaining tread depth of and are tires are deemed "worn out" when the tread is worn down to that point. The tire bead is the part of the tire that contacts the rim on the wheel. The bead is typically reinforced