If you don’t know what Unsprung Mass is, don’t worry - that’s what this article’s about. If you want to talk basics, the whole wheel/tire/brake system is called the Unsrpung Mass of the vehicle that you’re driving. The things that are supported by the suspension like the engine and the passengers are known as the sprung mass. The components of the unsprung mass include the axles, wheel hubs, wheel bearings, tires, and even the suspension links. If one of your vehicle’s brakes are mounted within/inside the wheel, their weight is also part of the unsprung weight. If you ever happen to notice, the Unsrpung Mass has an effect on your car’s acceleration and deceleration. The heavier your wheel is, the slower you go; it’s as simple as that.
So let us go over some physics : when the unsprung mass is higher, there’s more force on the sprung mass and therefore, your ride isn’t that comfortable. If there’s a high force applied to the spring of the suspension, that means that there is more pressure on the wheel to stay on the road; which means it affects the handling of your vehicle. That same force is also reacted by the actual body of the car. When this happens, the passenger of the vehicle feels that force, too. When the force is higher, that means that the ride is less comfortable.
Let’s say that you’re going through a parking lot and there’s those annoying bumps on the ground so you go “speed limit”. When you hit those bumps, you want your Factory 2008 Lincoln MKZ Rims and tires to move over the bumps as lightly as possible. When the wheel is lighter, the lower the forces involved. When you come across any bump or any imperfection in the road, you’ll notice that these cause tire compression - which means that it induces force on the unsprung weight. Within some time, the unsprung weight will then respond to this specific force with its own movement. When you have a lighter Factory Wheel on your car, it readily moves in response to the road bumps, that you annoyingly hit, with more grip when tracking over a road that’s imperfect. Because of this, lighter wheels are preferred on high-performance cars. If you have a heavier wheel on your vehicle, like an OEM Steel Rim, it won’t absorb as much vibration. When it hits the imperfections of the road, the unevenness will transfer to where the passengers are sitting and hence; cause an uncomfortable ride.
The Unsprung weight is a huge part of the vehicle’s suspension design AND a big part in the construction of the components that make up the suspension. When there’s beam axle suspensions installed on the vehicle, they usually have a heavier unsprung weight than your ordinary independent suspension systems; where the wheels are both suspended and allowed to move separately. There some heavy components, like the differential, that can be made part of the sprung weight by attaching them straight to the body. When there are light weight materials like plastic, carbon fiber, or even aluminum (like those 2004 Lincoln Aviator Wheels) these can supply further weight reductions at the charge of greater cost.
I guess you can say that that’s all there is to it .. if you get how the Unsprung Mass works. If you have any questions regarding the OE Wheels on you car, just visit us on OriginalWheels.com.