trucku - I just looked at the drawings and the shocks are gas charged. To answer your initial question, these shocks are probably entry-level shocks and the price usually reflects that. These shocks are tuned quite nicely so in terms of getting a crappy ride, I can guarantee that it won't be the case. Will they perform under extreme conditions like others costing twice or three times as much? No one can properly predict how these shocks will be used, but it all boils down to what you need them for. If you need them for serious off-roading where they'll be exposed to prolonged high-temperatures, then they're probably not the right fit. When we develop shocks we have a full understand of the "Achilles heel" of our competitors' shocks and we set targets depending on the design intent and application. We know exactly what makes others' twin-tubes and mono-tubes fail and that helps us make decisions.
We know that some use gas charging as a crutch in twin-tube applications where proper valve balancing between the piston and base valve is not present. We have predictive software to determine what the valving should be to maintain balanced flow. Gas charging is used to make oil flow more efficient through the valving - and yes in applications where the nitrogen is exposed to the oil, there will be some mixing resulting in an emulsion. However, all that is taken into consideration when a valve code is developed. If proper balance is maintained between the piston and the base valve, you don't really need gas charging for most standard applications. Gas charging results in a rod reaction force and also acts as an additional spring force, which results in (often unwanted) harshness. The benefits of gas charging are improved flow characteristics in compression and rebound. In Compression the gas in the reservoir maintains a constant preload on the oil, thus maintaining full pressure differential between the piston and the base valve. In Rebound the gas helps evacuate the oil from the reservoir into the working cylinder, thus greatly reducing cavitation. This is especially important to consider when designing shocks for smaller vehicles such as snowmobiles and ATVs and motorcycles (also check out our high performance rec. vehicle site
www.rydefx.com).
In monotubes, it's a whole different ballgame. Monotubes have a floating (dividing piston) which moves proportionally to the ratio of rod to bore diameter. Monotubes are high-performing dampers by design, by virtue of oil/gas separation. Oil being incompressible results in much more stable damping characteristics. Higher pressure nitrogen gas below the floating piston acts purely to balance out the oil flow through the piston. If the gas charge is too low, the floating piston will 'dump'. If the gas charge is way too high, the damping forces will fade (with increased temperature). When we design monotubes, there's a whole slew of different parameters to consider. High end monotubes may not always have room to package a floating piston in the main working cylinder and often communicate with a remote reservoir via a hose, in order to reduce deadlength or increase stroke capacity. Remote reservoirs also allow you to incorporate compression damping adjustment, so there's an added benefit.
In short, the shocks you picked out are entry-level aftermarket shocks with marginally improved performance over OE shocks. What you need them for will dictate if they'll perform acceptably or not on your application. We have a Gabriel 'Max-control' monotube produced overseas which was advertised a couple of years ago in Road and Track. I'm not sure if they're available to the US yet, but those would certainly be a great alternative.
I hope this information helps you make the best decision for your vheicle.
