Bolt circle
The bolt circle ( LK for short ) indicates the number and spacing of the threaded holes for wheels on automobiles . The number of holes determines the number of wheel bolts through which the tire with the rim can be mounted on the wheel hub. Depending on the car manufacturer and vehicle size, different bolt circles and different numbers of screws must be taken into account.
Types
A hole circle specification consists of the number of holes and the diameter in mm. The center of the hole or the stud bolt on the wheel mount of the vehicle is always on the bolt circle. Thus z. B. a bolt circle 4/100 from four wheel bolts, the distance between which is 100 mm diagonally. The hole circle diameter can be determined for any number of holes by measuring from the center of the hole to the center of the wheel or the center of the hub on the vehicle and doubling the distance. If the number of holes is even, you can also measure from one hole center to the opposite hole center. Only 3 and 5 are common with an odd number of holes, all other types consist of an even number of wheel bolts or studs. The use of a central nut does not result in a bolt circle specification.
Wheel centering
Furthermore, the wheel centering or vehicle center hole ( hub ) plays a decisive role in the selection of suitable attachments such as rims or spacers. The hub is the round protruding bolt onto which the wheel is pressed during assembly. Together with the wheel bolts, it serves as a holding point for the wheel and, thanks to its centering effect, prevents out-of-round running during operation. To determine this, the diameter is measured. Its diameter depends on the manufacturer and is specified together with the bolt circle, e.g. B. LK 4/108 65.1 or LK 4x108 65.1 .
Manufacturer criticism
With slightly different hub diameters, manufacturers prevent rims from other manufacturers from being fitted. ( Lock-in effect )
Rim selection
To select suitable rims for a vehicle, in addition to the bolt circle, the offset and the permitted sizes of the car tire with the appropriate load capacity and speed index for the vehicle must be known. This data can be found in the vehicle documents or requested from the vehicle manufacturer.
See also
- Generally for the diameter on which the center points of the holes lie, see hole pattern
- For screwing on car rims, see car rims
- For the screw connection of chainrings for cranks on the bicycle , see chainring