How are wheels measured?
Wheel or rim diameter is the distance measured in inches across the face of the wheel, from bead seat to bead seat. It’s measured this way because that’s where the tire and the wheel come together. (PRO TIP: You can find your wheel’s diameter on the back side of the wheel, usually stamped on one of the spokes.)
How do you read an alloy wheel size?
Typically, the alloy wheel size conforms to the following format:
- 20 x 8.5J.
- 4 x 100.
- 4 is the number of bolt holes, and 100 is the diameter of the PCD in mm.
- When increasing your car’s wheel rim diameter by 1 inch: increase the tyre section width by 10mm and decrease the tyre aspect ratio by 10 points.
What do the numbers mean on wheels?
The two-digit number that usually follows the tire’s section width tells us the aspect ratio, or tire profile measurement. A lower aspect ratio means a lower-profile tire with a shorter sidewall, while a tire with a higher aspect ratio will have a taller sidewall and look more like a donut.
What is the standard rim size?
WHEEL DIAMETER Diameter of the ‘rim’ in inches (excluding the tyre). Standard road cars generally have wheels that are between 14 inch and 19 inch in diameter. Luxury, sporty cars, SUVs and 4×4 vehicles generally have the bigger size wheels.
What is JJ in rim size?
J is the most common shape of a rim flange on passenger cars. The letter B appears at the smallest wheel sizes primarily for older car models, with diameters 12″ and 13″ and rim widths up to 5.0″. J rim contour has 17.5 mm high rim flange but B has only a 14 mm. JJ designation is most common on 4×4 and SUV vehicles.
How wide is 8.5 J?
Tyre overall rolling diameter
| Rim Width | Minimum tyre width | Maximum tyre width |
|---|---|---|
| 8.0 Inches | 215 mm | 245 mm |
| 8.5 Inches | 225 mm | 255 mm |
| 9.0 Inches | 235 mm | 265 mm |
| 9.5 Inches | 245 mm | 275 mm |
How do I know if alloys will fit?
There are 10 aspects that are critical for your choice of alloy wheel to fit properly:
- The Wheel PCD (Pitch Circle Diameter / Stud Pattern)
- The Front and Rear Wheel Offset (ET)
- The Wheel Diameter.
- The Front and Rear Wheel Width/s.
- The Front and Rear Tyre Size.
- The Wheel Load Capabilities.
- The Tyre Load Index.
- The Centre Bore.
What does 4×100 mean in rims?
Bolt pattern or bolt circle is the diameter of an imaginary circle formed by the centers of the wheel lugs. Bolt patterns can be 4-, 5-, 6-, or 8-lug holes. A bolt circle of 4×100 would indicate a 4-lug pattern on a circle with a diameter of 100mm.
What is JJ in rims?
“JJ” refers to the shape of the wheel’s flange (lip which holds the bead of the tire). JJ = 18.0mm high x 13.0mm wide, with a 13.0mm radius. J = 17.5mm high x 13.0mm wide, with a 9.0mm radius.