parts of car wheel

Overview of parts of wheel

The invention of the wheel is the first milestone in the era of transportation. Wheel changed the way of transportation. It starts using in a variety of applications. Furthermore, it became an important part of the automobile. Various parts of the car wheel make a perfect assembly for an automobile. Parts of the wheel and its information about its material and function are necessary for wheel selection.

Parts of the car wheel play an important role in their selection. Because its material decides its characteristics and strength. It helps to improve their aesthetics.

Car wheel parts diagram

parts of wheel

Parts of Car Wheel

  • Rim
  • Barrel
  • Outer Lip
  • Drop Centre
  • Flanges
  • Beads
  • Mounting Humps
  • Hub
  • Centre Bore
  • Plate
  • Spokes
  • Dish
  • Bolt Circle
  • Valve
  • Stem
  • Centre Cap
  • Lug Holes
  • Outboard Face

Parts of wheel with their description

Below are the different parts of the car wheel explained in detail.


Many people things that the wheel and rim are the same or vice versa. But in actual both are different. Rim is a part of the wheel. The wheel is an assembly of rim, hub, tire, valve, and more.

Rim is a cylindrical component that holds the tire on it. In the old design of wheel assembly, the tube is inside the tire. But in modern tubeless tires, it is necessary to maintain proper-fitting between tire and rim to avoid leakage of air because there is no different tube present like the old assembly.

Material selection is important for a rim. To withstand the various forces and whole car weight is necessary to have better strength. The size of the tire depends on the size of the rim. We can customize the rim and tire sizes as per our requirements. We can give different shapes and colors to the rims.


The barrel gives the shape and surface for mounting the tire. Its surface helps to maintain and retain the air pressure inside the tire.

Outer Lip

It is a wheel’s outer edge. When we drive the vehicle in a pothole, due to the high impact, it gets bend. It happens due to not getting that much support from the spokes.

Drop Centre

The drop center is the central and narrow part of the barrel. It gives support to the tire. To mount the tire properly on the rim, one side of the tire gets inserted into the drop center. So that the other side can adjust to hold on to the edge of the rim.


Flanges prevent the tire from slipping while a car running on the road. These are at both ends of the wheel. It also prevents slippage of the tire during harsh conditions like heavy rides, uneven roads, etc.


It helps to fit the tire on the wheel and create a seal. Beads and flanges are part of the wheel assembly.  

Mounting Humps

These are the ridges that go around both sides of the barrel. Humps lead to separate beads and hold the tire on the wheel. Slant edges of the hump help during the maintenance. In some of the cars or sports cars, these edges are straight to prevent the tire from sliding off from the rim. It helps to make tires on the rim at high speed.


Hub is a central part of the wheel. On one end of the hub brake drum mounts and the other end wheel bearing. Hub has a center hole to engage with the axle. So, we can insert the hub in the axle, and with the stud, we can fix the wheel on the axle.

This part holds the rotor, brake pad, calipers, and others. So, we can run the vehicle on the road and apply breaks whenever required.

Centre Bore

The function of the center bore is to support the weight of the vehicle. It is at the center and on wheels backside.

Centre disc or Plate

The plate is to fix every component of the wheel to the axle. It has a hole on its periphery to fix with the axle.


Spokes are the structural member that connects the rim and hub. It is for the structural integrity of the wheel. In some vehicles, it is inbuilt with a rim, and in some vehicles it is separate.

It improves the aesthetics of the vehicle and makes it unique from others vehicles. We can customize it as per our requirements.

5 spokes wheel is common, but we can see the vehicle with 3 spokes and more than 5 spokes. Fewer spokes reduce the weight of the wheel assembly.

It helps to absorb impact forces during driving. So the material of the spokes plays an important role in their strength.

Bolt Circle

It is an area created by the lug bolt. It can vary as per the vehicle and manufacturer.


The valve mechanism in the car is to evaluate and monitor the air pressure inside the tire. It helps to avoid any damage or accident due to less air pressure inside the tire. Rubber stems are commonly used in vehicles. Others are also there, which are made up of metal to increase aesthetics.

Centre Cap

The center cap is the center area of the wheel where all spokes come together. It fits on the center hole, and we can remove it. But in the steel rims, we can not remove the center cap.

We can drive a vehicle without a center cap. In modern vehicles, their logo is on the center cap. So it improves the aesthetics and covers the hole as well.

Lug Holes

Lugholes are the holes around the center bore. It is for passing bolt to attach wheel with the axle. We can fix the wheel assembly with the axle by the nuts. These lug holes vary as per the manufacturer. Some manufacturer uses 4 lug holes, and some use 5, 6, and 8.

Outboard Face

It is an outer side of the wheel after fixing with the vehicle. It improves the aesthetics of the vehicle.

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