Car With Rims

On bicycles, the optimum tire width is approximately twice the rim's internal width (e.g. a 35mm tire on a rim with an ETRTO 17mm internal width) or one-and-a-half times the rim's external width. Considerable variation outside this range is safe, but very wide tires on a narrow rim can overstress the rim and damage the tire sidewalls, whereas very narrow tires on a wide rim give a hard ride and can result in a high-pressure tire blowing off.
Production
A standard automotive steel wheel rim is made from a rectangular sheet metal. The metal plate is bent to produce a cylindrical sleeve with the two free edges of the sleeve welded together. At least one cylindrical flow spinning operation is carried out to obtain a given thickness profile of the sleeve — in particular comprising in the zone intended to constitute the outer seat an angle of inclination relative to the axial direction. The sleeve is then shaped to obtain the rims on each side with a radially inner cylindrical wall in the zone of the outer seat and with a radially outer frusto-conical wall inclined at an angle corresponding to the standard inclination of the rim seats. The rim is then calibrated.