Ride height
Encyclopedia
Ride height is the amount of space between the base of an automobile tire
and the underside of the chassis
; or, more properly, to the shortest distance between a flat, level surface, and any part of a vehicle
other than those parts designed to contact the ground (such as tires, tracks, skis, etc.). Ground clearance is measured with standard vehicle equipment, and for car
s, is usually given with no cargo or passengers.
Ground clearance is a critical factor in several important characteristics of a vehicle. For all vehicles, especially cars, variations in clearance represent a trade-off between handling
and practicality. A higher ground clearance means that the center of mass of the car is higher, which makes for less precise and more dangerous handling characteristics (most notably, the chance of rollover
is higher). However, it also means that the car is more capable of being driven on roads that are not level, without the road scraping against and likely damaging the chassis and underbody. Higher ride heights will typically adversely affect aerodynamic properties. This is why sports car
s typically have very low clearances, while off-road vehicle
s and SUVs have higher ones. Two well-known extremes of each are the Ferrari F40
and the Hummer
.
For armored fighting vehicles (AFV), ground clearance presents an additional factor in a vehicle's overall performance: a lower ground clearance means that the vehicle minus the chassis
is lower to the ground and thus harder to spot and harder to hit. The final design of any AFV reflects a compromise between being a smaller target on one hand, and having greater battlefield mobility on the other. Very few AFVs have top speeds at which car-like handling becomes an issue, though rollovers can and do occur. By contrast, an AFV is far more likely to need high ground clearance than a road vehicle.
Lowering a car's suspension
is a common and relatively inexpensive aftermarket modification. Many people prefer the more aggressive look of a lowered body, and there is an easily realized car handling
improvement from the lower center of gravity. Most passenger cars are produced such that one or two inches of lowering won't increase the probability of damage significantly. On most automobiles, ride height is modified by changing the length of the suspension springs
, and is the essence of many aftermarket suspension kits supplied by manufacturers such as Eibach
and H&R
.
Some cars have used underslung frames to achieve a lower ride height and the consequent improvement in center of gravity. The brass-era cars of the American Motor Car Company
are one example.
Self-leveling suspension systems are designed to maintain a constant ride height regardless of load. Vehicles not equipped with self-leveling will pitch down at one end when laden; this adversely affects ride, handling, and aerodynamic properties.
Some modern automobiles (such as Audi's Allroad Quattro
) have adjustable suspension systems
, which can vary the ride height by locating the suspension mounting points, depending on road conditions and/or the settings selected by the driver.
Other, simpler suspension systems, such as coilover
springs, offer a way of manually adjusting ride height (and often, spring stiffness) by compressing the spring in situ
, using a threaded shaft and adjustable knob or nut.
18-wheel tractor trailers also have to take the ground clearance of both their tractor and especially trailer into consideration on certain areas of uneven terrain, such as raised railroad crossings. Their extremely long wheelbase means that such terrain could potentially catch the undercarriage of the trailer in the wide space between the axles, potentially leaving the truck stuck with no means to extricate itself.
Tire
A tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...
and the underside of the chassis
Chassis
A chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame with the wheels and machinery.- Vehicles :In the case of vehicles, the term chassis means the...
; or, more properly, to the shortest distance between a flat, level surface, and any part of a vehicle
Vehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....
other than those parts designed to contact the ground (such as tires, tracks, skis, etc.). Ground clearance is measured with standard vehicle equipment, and for car
Čar
Čar is a village in the municipality of Bujanovac, Serbia. According to the 2002 census, the town has a population of 296 people.-References:...
s, is usually given with no cargo or passengers.
Ground clearance is a critical factor in several important characteristics of a vehicle. For all vehicles, especially cars, variations in clearance represent a trade-off between handling
Handling
Handling stolen goods is the name of a statutory offence in England and Wales and Northern Ireland. It takes place after a theft or other dishonest acquisition is completed and may be committed by a fence or other person who helps the thief to realise the value of the stolen goods...
and practicality. A higher ground clearance means that the center of mass of the car is higher, which makes for less precise and more dangerous handling characteristics (most notably, the chance of rollover
Rollover
A rollover is a type of vehicle accident in which a vehicle tips over onto its side or roof. The most common cause of a rollover is traveling too fast while turning.- Dynamics :Vehicles can roll over in several ways...
is higher). However, it also means that the car is more capable of being driven on roads that are not level, without the road scraping against and likely damaging the chassis and underbody. Higher ride heights will typically adversely affect aerodynamic properties. This is why sports car
Sports car
A sports car is a small, usually two seat, two door automobile designed for high speed driving and maneuverability....
s typically have very low clearances, while off-road vehicle
Off-road vehicle
An off-road vehicle is considered to be any type of vehicle which is capable of driving on and off paved or gravel surface. It is generally characterized by having large tires with deep, open treads, a flexible suspension, or even caterpillar tracks...
s and SUVs have higher ones. Two well-known extremes of each are the Ferrari F40
Ferrari F40
The Ferrari F40 is a mid-engine, rear-wheel drive, two-door coupé sports car produced by Ferrari from 1987 to 1992 as the successor to the Ferrari 288 GTO. From 1987 to 1989 it was Ferrari's fastest, most powerful, and most expensive car...
and the Hummer
Hummer
Hummer was a brand of trucks and SUVs, first marketed in 1992 when AM General began selling a civilian version of the M998 Humvee. In 1998, General Motors purchased the brand name and marketed three vehicles: the original Hummer H1, based on the Humvee; and the H2 and H3 models that were...
.
For armored fighting vehicles (AFV), ground clearance presents an additional factor in a vehicle's overall performance: a lower ground clearance means that the vehicle minus the chassis
Chassis
A chassis consists of an internal framework that supports a man-made object. It is analogous to an animal's skeleton. An example of a chassis is the underpart of a motor vehicle, consisting of the frame with the wheels and machinery.- Vehicles :In the case of vehicles, the term chassis means the...
is lower to the ground and thus harder to spot and harder to hit. The final design of any AFV reflects a compromise between being a smaller target on one hand, and having greater battlefield mobility on the other. Very few AFVs have top speeds at which car-like handling becomes an issue, though rollovers can and do occur. By contrast, an AFV is far more likely to need high ground clearance than a road vehicle.
Lowering a car's suspension
Suspension (vehicle)
Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. Suspension systems serve a dual purpose — contributing to the car's roadholding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants...
is a common and relatively inexpensive aftermarket modification. Many people prefer the more aggressive look of a lowered body, and there is an easily realized car handling
Car handling
Automobile handling and vehicle handling are descriptions of the way wheeled vehicles perform transverse to their direction of motion, particularly during cornering and swerving. It also includes their stability when moving at rest. Handling and braking are the major components of a vehicle's...
improvement from the lower center of gravity. Most passenger cars are produced such that one or two inches of lowering won't increase the probability of damage significantly. On most automobiles, ride height is modified by changing the length of the suspension springs
Spring (device)
A spring is an elastic object used to store mechanical energy. Springs are usually made out of spring steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication...
, and is the essence of many aftermarket suspension kits supplied by manufacturers such as Eibach
Eibach
Eibach stands forPlaces* a borough of Nuremberg, see Eibach * a borough of Dillenburg, see Eibach Rivers* a stream located in Swiss canton Basel-Country, see Eibach Buildings...
and H&R
H&R
H&R may refer to:*H&R Block, a tax preparation company*H&R Firearms, a firearm manufacturer...
.
Some cars have used underslung frames to achieve a lower ride height and the consequent improvement in center of gravity. The brass-era cars of the American Motor Car Company
American Motor Car Company
The American Motor Car Company was a short-lived company in the automotive industry founded in 1906, lasting until 1913. It was based in Indianapolis, Indiana, United States. The American Motor Car Company pioneered the "underslung" design.-History:...
are one example.
Self-leveling suspension systems are designed to maintain a constant ride height regardless of load. Vehicles not equipped with self-leveling will pitch down at one end when laden; this adversely affects ride, handling, and aerodynamic properties.
Some modern automobiles (such as Audi's Allroad Quattro
Audi Allroad Quattro
The Audi allroad quattro and the subsequent Audi A6 allroad quattro are crossover estate executive cars, manufactured and marketed by German automaker Audi since 1999...
) have adjustable suspension systems
Height adjustable suspension
Height adjustable suspension is a feature of certain automobile suspension systems that allow the motorist to vary the ride height or ground clearance. This can be done for various reasons including giving better ground clearance over rough terrain, a lower ground clearance to improve fuel economy...
, which can vary the ride height by locating the suspension mounting points, depending on road conditions and/or the settings selected by the driver.
Other, simpler suspension systems, such as coilover
Coilover
A coilover is an automobile suspension device. "Coilover" is short for "coil spring over strut". It consists of a shock absorber with a coil spring encircling it. The shock absorber and spring are assembled as a unit prior to installation, and are replaced as a unit when the shock absorber has...
springs, offer a way of manually adjusting ride height (and often, spring stiffness) by compressing the spring in situ
In situ
In situ is a Latin phrase which translated literally as 'In position'. It is used in many different contexts.-Aerospace:In the aerospace industry, equipment on board aircraft must be tested in situ, or in place, to confirm everything functions properly as a system. Individually, each piece may...
, using a threaded shaft and adjustable knob or nut.