So if you are like me it took a while to get down to the nitty gritty of tuning your RC car or truck. The reason for my lateness to the world of tuning is simply because I never needed it. I spent the vast majority of my time outside with my trucks bashing away, not really paying much attention to “meaningless” things like shock oil. The truth is it was my own ignorance that kept me from enjoying a whole new level of fun! Tuning my trucks has become one of my favorite past times and running different shock oil weights has become my newest discovery.
There are a lot of reasons why you would choose to run different oils. It really depends on the terrain you are running on and how you want your shocks to react to certain changes in terrain. If you are launching your RC truck off loads of jumps you’re going to want to pay special attention to this. Most people tend to lean towards heavier weight shock oil in the front, mostly because the entire weight of the vehicle comes down on the front when jumping. (If everything went well ) The reality is you want to try and level off as much as you can when you land, its just not that easy. On top of that the real reason you should run a little heavier shock oil in the rear is simply because the majority of the vehicles weight resides there.
One of the things you will notice if your shocks do not have enough resistance is a lot of bottoming out. A word of caution on that, if you add too heavy weight shock oil you can end up with bent axles. This occurs when people put too heavy of an oil in their shocks and pre-loading their springs to much. As soon as you take away the damping on the shocks by using really thick oil, you end up putting the pressure of the landing in to the wheels and the axles and that’s when things go and break on you.
The real key is to look at your conditions and decide how you want your vehicle to react. If there are a lot of little bumps and you want it to absorb those instead of bouncing all around consider running lighter weight shock oil. If you are running at slow speeds and you want your RC to absorb a lot of the bumps something like 30 weights would be just fine. If you are running a lot faster, or racing on a track you are going to want to increase the weight. It is going to decrease the chances of the chassis bottoming out and is going to handle the weight transfer of your vehicle better when breaking and accelerating.
Remember, when adding shock oil protect your counters and everything else by using a towel. It spills easy and I have a nice little stain on my carpet that the wife points out to me every chance she gets.