SUSPENSION TERMS
- Air Bump – A very small shock designed specifically for preventing bottoming out. Valving and nitrogen charge can be changed to help soften or stiffen up bottom out events.
- Air Shock – A shock which uses a large diameter shaft to act as a spring and damper. Air shocks are popular for light weight rock crawlers.
- Bleed – A hole through the piston through which oil can pass unrestricted. Learn more about bleed holes and piston design here.
- Bypass – A shock which has external damping adjustment for predefined regions. Each bypass zone can be adjusted independently. Learn more about Bypass Shocks here.
- Coilover – A threaded body shock which has coilover spring(s) installed on it. Coilover shocks have a lot of adjustability and performance benefits. Learn more about coilover shocks here.
- Connecting Members – Things connecting sprung and unsprung weight such asUpper and Lower Control Arms, suspension links and leaf springs.
- Corner Weight – The weight of one corner of the vehicle. Left and right sides may be slightly different. For our calculators it is recommended to provide averages of left and right corner weights. Corner weights can refer to total weight or sprung weight so its important to clarify when providing total weights.
- Dual Rate – A coil spring setup using two stacked coil springs, commonly with a cross over point when the upper spring stops collapsing and transitions fully to the lower spring rate. A dual rate spring setup is very common on coilovers for custom vehicles. There is usually a wide variety of spring options to choose from which will help get a very specific spring combination.
- Flutter Stack – A type of shock valving where smaller diameter disks are inserted in between larger diameter disks.
- Motion Ratio – How much the shock moves in relation to how much the wheel moves. A motion ratio of 0.5 would mean the shock moves one inch for every two inches the wheel moves. A motion ratio of 1:1 means the shock is mounted straight to the axle and the shock is positioned 90 degrees to chassis.
- Preload – The amount of spring tension applied when the suspension is at full droop (limit straps installed). This is often measured in inches. Preload is most commonly measured at the shock, but can also be measured at the wheel for comparisons between vehicles.
- Pyramid Stack – A type of shock valving where many valve disks are used, and each one gets progressively smaller or larger, and looks like a pyramid.
- Smoothie – A smooth body shock.
- Spring Rate – Upper and lower springs each have their own rate, when combined they form a new, softer rate defined by the following equations.
- Sprung Weight – Everything on top of the springs and shocks, includes roughly 2/3 the weight of connecting members. Spung weight would not include tires, wheels or axle.
- Triple Rate – A dual rate setup with very short third upper spring which quickly goes solid. This setup is reserved for unique setups. Often time the shorter top spring is called a “Tender Coil”. Learn more about Tender Coils here.
- Unsprung Weight – Weight of everything below the springs such as tires, wheels, solid axles, and roughly 1/3 the weight of connecting members.
- Wheel Rate – This is the spring rate at the wheel, it takes into account the suspension motion ratio and is useful for comparing across vehicles.
- Wheel Travel – This refers to the total up and down travel a wheel will move during full suspension cycle. With large motion ratios, the wheel travel can be more than double the shock travel.
Leave a Reply
Want to join the discussion?Feel free to contribute!