help you out here.
"For example, the actual "rc2x"... what does that mean/ stand for?"
RC2x is Zocchs accronym for the damping system in the 888 and 66 RC2x models. All it stands for is Rebound (R), Compression (C), times 2 (2x). What it is, a combination of Low speed rebound and compression damping circuits (both adjustable), and a high speed compression damping circuit which is also adjustable.
"Also the "Lite" one?"
I assume you are talking about the 66 Light here. There are two models that are lighter in weight than the RC2x and the VF2 models, The "Light" and the SL (Super Light). The Light saves weight by using a one side coil and one side air spring configuration and on using only the RC2 system rather than the RC2x damper. The SL is a totaly air sprung fork and saves weight over the Light in this way. Anyway, thats the way it's SUPPOSED to work, however, the Light is actually a tad heavier than the RC2x model, about 6 grams I think. The lightest of the 66 series is the SL with a "claimed weight of 2560 grams.
"For rear Shocks how does/ what does rebound, spring preload do for riding?"
Rebound is the same for rear shocks as it is for forks, it referes to rebound damping. And just like forks it keeps the shock from rebound to quickly and bouncing you around. Spring preload is also the same for forks and shocks. How it is accomplished is a bit different in some cases though. For most coil shocks preloading the spring is accomplished by turning the knurled ring that sits atop the coil spring clockwise. This puts pressure on the spring "preloading" it. This is used to set how much the rear suspension "sags". Sag is the amount that a fork or shock compresses while you are simply sitting on the bike. Sag allows the fork or shock to follow the terrain while you ride. In other words, with the proper amount of sag the suspension will not only soak up bumps but will also follow holes as well. This helps keep your wheels in contact with the ground as much as possible and makes for better traction. That's with a coil fork or shock, and is called "mechanical preload". With air forks or shocks there is no mechanical adjustment because the amount of air pressure is used to set preload and sag. Another function of preload is to tune the ride as well. More preload and less sag equals a stiffer ride, less preload and more sag equals a squishier ride.
"What does the "piggy-back" oil resovior(sp?) do?"
One of the problems with an oil damped shock became evident years ago as Down Hill racers and Freeriders got more aggressive and the courses became more technical. They started blowing the seals in their shocks. The reason being was the bigger hits, higher speeds, big drops, jumps, etc. These would build tremendous pressure in the dampers as they tried to do their job. A big enough hit and you'd blow the seals, the damper would fail.
The solution was to put more oil in the system. To do this a piggy back resivour was added. This increased oil volume and gave the oil some place to go on big hits, gave a wider adjustment range, kept the oil cooler, and generally increased damping performance. You see them mostly on shocks designed for DH and Freeride big hit peformance.
"Also, what is high speed/ low speed compression?"
They are just exactly what the names state, high speed and low speed damping. This however does not refer to the speed of the bike (it can be related to speed though) but rather the speed of the compression and/or rebound of the fork or shock. Basically it refers to two DIFFERENT circuits in the damper. One effects low speed compression/rebound the most, the other affects high speed. It used to be that most forks were set up with low speed circuits as most riding involved cross country and technical riding with 80 or 100mm suspension, where compression and rebound speeds were fairly slow. But todays styles of riding and longer travel suspension systems have pushed the envelope and high speed circuits have been added to the dampers in many higher end forks and forks designed to more aggressive riding. Longer travel forks have more range of motion, thus more room to acclerate. This requires different valving to handle the extra compression and rebound speeds that are achieved and keep the bike under control. Thus the High Speed damping. But you still need low speed damping as well, because you're not always bombing down hill with your hair on fire!
So manufacturers produce forks that have both high and low speed circuits in the same damper. In many instances both high and low speed circuits are independently adjustable as well.
There's a lot more that to than what I've covered above, but in the intrest of simplicity that's pretty much it in a nut shell. What you actually need is dependent on your riding style, suspension travel, etc. If you are riding a 100mm travel bike and riding pretty much XC/Trail moderately agressively, then you don't need all them bells and whistles. But if you are riding a 150mm travel All Mountain style bike, doing drops, jumps, and love fast down hills, then the extras are a good idea. They'll impove the ride, suspension peformance, overall control over the bike, and allow for custom tunning of the suspension for the terrain being ridden.
Hope this helps you out a bit. Not the deffinitive explanations for your questions, but the basic ideas for each.
Good Dirt
