How do I measure a wheel rim?

The 'pcd' (pitch circle diameter) is the measurement you will always be asked for when enquiring about a wheel rim.

Number of Rim Studs

3 Stud Rim
Measure C, this is the distance from the centre of a stud to the edge of the hub centre. Measure D, this is the hub centre diameter. pcd = (C x 2) + D

4 Stud Rim
Measure across the centre hub
from the centre of one stud to
another, this is the 'pcd'

5 Stud Rim
Measure C, this is the distance from the centre of a stud to the edge of the hub centre. Measure D, this is the hub centre diameter. pcd = (C x 2) +D

 

The other measurements needed will be:-

1) The wheel rim diameter, this can be obtained from the information on the tyre
eg. 520x 10, 175x13, 650x16, etc...

2) The wheel section, this is normally stamped in the rim. This a number followed by a letter eg. 4½ J, 5 J, 5½ J etc....

3) The 'offset' is then another factor to consider, if A is equal to B, it is a centre web rim, if A is greater than B, the rim has an offset.

Disclaimer

The information in this guide is as accurate as the writer is able to make it, however, no responsibility can be accepted for any inaccuracies which may be in the text. It is the responsibility of any person wishing to depend on the facts to check for themselves with original documentation or any updating regulations, instruments or changes in the law. Interpretation of the law is a matter for the courts.