Universal Rear Shock Absorber Suspension
Technically speaking, one can mount a remote Universal Rear Shock Absorber Suspension reservoir shock and a piggyback shock upside down and still work but one would still refrain from doing so. Being compact and they are easier to fit than the other ones and also more economical than them. But it still is nitrogen charged shock, but the emulsion contains in it the charge along with the oil and the pressure tube. This makes it a challenge to fit. It can only be mounted right side up.
A piggyback coilover shock is somewhat identical to a remote reservoir shock the only difference being that the reservoir is mounted directly on the shock with a bracket that incorporates a hydraulic passage between the reservoir and the cylinder, instead of being attached to the shock with a flexible hydraulic hose. They are of high quality, compact and easy to fit. It also provides a remarkable ability for its position to be adjusted whenever a transition in the spring rate occurs. Most of the coilovers would be categorized either as a remote reservoir, piggy back or an emulsion coilover. They also allow the selection of specific spring rate to achieve any targeted suspension frequency and also re-adjustable to achieve suspension height or target ride height.Although there isnt anything magical about coilovers but they definitely have a number of advantages. Its parts are separately available at reasonable prices.
An emulsion coilover shock is different from the other two and has neither a reservoir nor floating piston. It is also easy to set up a coilover for use with a combination of springs which provides a soft to firmer spring rate depending upon the compression of suspension. It is pretty easy to modify or adjust valving to suit the riders needs. It also comes with an adjustable top spring seat which provides the advantage of adjusting the ride height. Its resistance to foaming, aeration and fades than the external ones is less and is best suited for light weight and low-speed vehicles.
The above discussion might not clear the air in your mind but eventually you shall figure it all out after we discuss the various types of coilovers, their parts and functions