Technical advice

The use of wheel spacers in conjunction with steel rims is only possible if the steel rims have a flat contact surface.

If the spacers are stuck on the axle, heat the spacers with a hot air gun. The heat causes the aluminum to expand slightly so that the spacers can be removed without using force. Before installing the spacers again, make sure to grease the wheel hub (see installation instructions).

All offset limits specified in the catalog (without * marking) are the 2% limits specified by the legislator. This means that the legislator permits track widening of 2% without the vehicle in question having to undergo additional testing. This 2% limit is calculated from the track width. The track width is measured on a vehicle with the standard tires. It is measured from the center of the tire to the center of the tire. For most passenger cars, a track width of 1500mm can be assumed. This usually results in a permissible track widening of 15mm per side. Whether you are still within the specified offset limit, you can calculate as follows: Offset of your rim minus thickness of the wheel spacer per side must not fall below the specified offset limit. All offset limits marked with /* are values tested by us beyond the 2% limit. I.e. we have had the TÜV or DEKRA check whether the vehicle in question can withstand a wheel spacer beyond the generally approved value. These offset limits are not generally included in the certificate for the wheel spacers and may be associated with additional costs. In addition, we have further chassis strength certificates of about 250 vehicles. So if you don't find your vehicle in our list or not with the required offset limit, please ask us.

Part certificates
If a parts certificate is available for your vehicle, you will find it directly with the vehicle on our website.

 

In contrast to a general operating permit ("ABE"), components / modifications to vehicles for which there is a parts certificate must be tested by a state-approved testing organization (TÜV, DEKRA, KÜS, etc.). Simply carrying the parts certificate in the vehicle is not sufficient. The scope of coverage and any conditions of the parts certificate must be checked in any case before purchase! If the parts certificate does not cover your case, our general strength certificate automatically comes into force.

Strength certificates
For vehicles for which there is no parts certificate, as well as for special spacers and adaption wheel spacers, there is a general strength certificate according to §21 StVZO.

Together with this, an individual acceptance at the TÜV (West Germany, old federal states) or at the DEKRA (East Germany, new federal states) is required. You can download the strength certificate here. The coverage and possible conditions of the strength certificate must be checked in any case before the purchase!
Read also: 2% - limit, offset - limit, chassis strength

Pitch circle diameter (PCD)
The pitch circle diameter describes the diameter on which the holes for the wheel bolts are located. In addition to the diameter, the number of holes is also decisive. An example for the specification of a pitch circle is "100/4" - 100mm is the diameter on which the 4 holes are arranged.
Here you can purchase our pitch circle gauge.

 

Hub
The hub is the center hole of the rim by which the wheel is mounted and centered on the wheel hub of the vehicle.

Please check which wheel bolts/nuts or knurled studs you require before ordering your product.

 

Thread
The thread diameter and the pitch must be taken into account when specifying the thread. What the thread pitch is, can be explained best with an example. Threads are specified as follows: "M14x1,5" - stands for the diameter 14mm, 1.5 for the thread pitch - with a full turn of the screw/nut, the screw-in depth here is 1.5mm. Other examples are "M12x1.5", "M12x1.25", "M14x1.5" or 1/2" UNF, 3/8" UNF, etc. However, in order to perform an accurate measurement, a bolt measuring gauge is required. You can purchase these in our online store.

Head shape
Three different head shapes are used by manufacturers:

-  Conical collar: Conical shape 60 °
-  Spherical collar: Hemispherical shape in the radii 12mm, 13mm or 14mm - The correct radius is absolutely necessary here!
-  Flat collar: Flat collar

We offer all screws in one and two parts. If the original screws are two-piece, always use two-piece screws. If the manufacturer used one-piece bolts, both one-piece and two-piece bolts can be used.

Please also read our note on wheel bolts with offset

Shaft length
Shaft length is the measurement between the start of the bolt and the start of the above mentioned conical, spherical or flat collar head of the bolt.

Note on knurled bolts: Note on knurled bolts: For knurled bolts, the length is measured from the beginning of the bolt to the end of the knurling. The knurling must be measured as well, the head must not be measured.
The measurement of the knurl diameter is also important. The specification of the knurl height is not absolutely necessary.
Have a look at our PDF for measuring knurled bolts!

Pitch circle offset bolts are used to adapt different pitch circles if the pitch circles differ only slightly. There is a certificate for pitch circle offset bolts, you can get this on request from us. The certificate is personalized (with name and chassis number).

Type means the type according to line 3 in your vehicle registration certificate. Check if the type corresponds with the one in our catalog. Please note that it is also possible that the same vehicle type was manufactured with different pitch circles.