Before we talk about Valving option lets understand the 3 different bleed circuit that we use most often. The 3 option are as such: 4 bleed full, 4 bleed tiny, and 1 bleed tiny, this create different amounts of bleed which determines how fast the shock will allow the car to square up or get back to zero. We use these bleed systems in different shocks and under different times, but understanding how bleed changes your car and how much you need to change the bleed to get that effect is the trick.
4 Bleed Full: This bleed shim is used in all 12 Series shocks that are called out as such, (2020) or we call this a number / number call out. Any number/number call out in any configuration will use a 4 bleed shim on both sides of the piston, this is true in both 36mm and 46mm shocks. What this means is that it will never have great low speed control over the car but allow the car to get across rough better, but lack in posture control in the slick.
4 Bleed Tiny: This bleed shim starts to reduce the amount of bleed that the shock see, slowing down how fast the car returns to zero. We use this shims in both the 36mm and 46mm shocks and in a shock the has specific low speed callouts such as a RF1-75/130. This type of valving is good to the cars posture while allow it to slowly return to zero. This allows for both front end grip and drive in the car at the same time.
1 Bleed Tiny: This bleed shim is used to reduce the bleed to the fullest but still allow the shock to work. No bleed shocks are on the market but can only be run under certain condition making them not the most desirable valve for a dirt car. This shim is use most in the RFGF family of shocks when we are need to hold the shock in that position longer to all the time. This is good when running a bump stop or when you need to maintain control of the car longer.
In a 12 Series shock we don't build the RFGF2 stuff, and shouldn't build the GF stuff, we need to work on rebound and car control before we jump way out of hand on rebound. We need to turn balance these cars in order to be fast. We need low speed control and grip to make them go fast, not just a ton of rebound, but rebound that works. We can build any valving and the most common are in bold.
RR 150/160 @100psi
LR 152/225 @150psi
RR 150/160 @100psi