Every car, from a Ferrari to a Ford Pinto, relies on the simplest of machines to operate: the wheel. There’s no getting around it (pun intended)—right next to fire, the wheel might be the greatest discovery man has ever made.
Without wheels and tires, cars and trucks would be little more than expensive lawn ornaments. From car to car, wheels and tires perform the same function; the only difference is in the size, style, and structure.
To increase your knowledge base of cars, trucks, and how they work, we explore the basic parts of a car wheel. Knowing more about your vehicle will help you care for it better and keep it running for many years.
Car Wheel Parts Diagram with Name
Car Wheel Parts Names List:
- Wheel Rim
- Valve Stem
- Hubcap/Wheel Cover
- Center Cap
- Lug Nuts
- Wheel Studs
- Wheel Spacers
- Wheel Bearings
- Wheel Seal
- Wheel Bolts
- Wheel Locks
- TPMS Sensor
- Rim Flange
- Wheel Balancing Weights
- Wheel Valve Cap
- Dust Cap
Parts of a Wheel
There are various parts of a car wheel, which include three main parts: the tire, the rim, and the hub. The tire, which is the width of the wheel, goes around the rim and gives the wheel grip on the road surface. The hub is where the wheel attaches to the axle of a car.
#1. The Tire
This is pretty simple and obvious. We all know where the tire is and what it looks like. The tires are important for the car and how smooth the ride is. The tires keep the ride nice and smooth because you’re riding on air, literally.
The modern tire is around 70 years old, and prior to this, they were solid rubber and offered little in the way of cushioning. Having the right kind of tire on your car is important for safety. Tires grip the road in wet, icy, and snowy conditions and improve handling in adverse conditions.
#2. The Rim
If the tire is the skin, then the rim is the skeleton of the wheel assembly. The tire wraps around the rim, and it supports the tire, giving it form and allowing air to fill it. Rims are typically made from steel or aluminum and come in hundreds of different styles.
They can come with plastic hubcaps or in polished chrome to dazzle the eye. The style of rim varies from car to truck. Trucks need a beefier rim to support more weight and trend toward function over form. The diameter and width of the rim will dictate what style and size tire will fit on it.
#3. The Hub
The hub is the center part of the wheel that the rim attaches to. It’s home to brake pads, calipers, and rotors. All of that attaches to the axle and allows the vehicle to move and stop.
The tire is attached to the hub, and from its center, five bolts extend, along with lug nuts. The hub is home to the mechanics of the wheel and keeps it attached to the vehicle.
The hub refers to the central part of the wheel that attaches to the car’s axle, consisting of the center bore, the center disc, the lug holes, and the center cap.
Spokes are structures that connect the hub and the rim. They are the source of the wheel’s structural integrity. Together with the hub, spokes form the wheel’s outboard face. On multi-piece wheels, the wheel face is produced as a separate piece and bolted to the inside of the barrel.
Spokes also provide aesthetic value and are a major part of what makes a wheel unique. Custom wheels come in various spoke styles for visual appeal, with spokes varying in quantity, width, shape, and pattern. Some truck or trailer wheels may have solid faces with no spokes at all!
Five-spoke wheels are a common wheel design due to engineering reasons: each spoke is supported by two opposing spokes that reduce torsional vibration. A low spoke count also equates to lower wheel weight. That said, the number of spokes on a car wheel has very little effect on weight or performance, especially compared to the materials and construction methods used, so just pick the wheel that you like most.
#8. Outer Lip
The outer lip is the portion of the wheel in front of the spokes. For the most part, the dish only comes into play when it is a large area. When the spokes are significantly distanced from the outer edge, the wheel is considered a deep-dish wheel.
This is done purely for aesthetic reasons. As the dish gets deeper, the face is more vulnerable to damage from impact.
The barrel is the very outer portion of the wheel, which creates the structures necessary for mounting the tire. The barrel has many parts. The smallest inside diameter of the barrel is the drop center.
If the drop center is close to the front face of the wheel, it is a front mount wheel. If the drop enter is close to the back face of the wheel it is a reverse mount wheel.
The barrel edges are flared to create flanges. The flanges keep the tire from slipping off. The outer facing flanges are part of the cosmetic face of the wheel.
Just inside the flanges are flat areas called beads. This is where the edges of the tire sit onto the wheel.
Flared edges along the inboard and outboard sides of the rim. These help to prevent the tire from slipping off the wheel.
#12. Mounting Humps
Small ridges that run along the inside of each bead rest. These help to prevent the tire beads from slipping and hold the beads in place against the wheel.
#13. Drop Center
The narrowest part of the barrel is used to mount the tire on the wheel without overstretching the bead wires.
#14. Center Cap
A removable piece that covers the center bore on the outside. On many cars today, it may also serve to protect the lug nuts from damage.
#15. Valve Stem
The rim features a hole for inserting a valve stem when mounting a tire. This is a metal-air valve used to inflate the tire and monitor its air pressure.