- Shock Mounting Locations & Tuning -

Today’s r/c race cars have multiple shock locations both on the towers and on the arms. Some even allow for the tower/shock location to be moved from the front of the arms to the rear of the arms in the rear of the car. Let’s keep this “Tip of the Week” more simple and focus on basic shock location tuning.

Front Shock Locations:

Shocks mounted towards the inside of the car or “In on the tower” gives the car a more progressive feel to the car. This means that the initial movement will be soft, as the suspension cycles through its stroke it will become more stiff. This is often referred to as “progressive” since as the suspension cycles through it’s travel, the shock “feel” becomes increasingly stiffer.  Conversely moving the shock out on the tower will make the shock more linear in feel.  This often frees up the car as well as improves jumping and bump handling.  Outward positioned shocks also help curb excessive body “roll” and increases the cars response.

Arm location on the shocks is also important. Shocks mounted further inward on the arms gives the car a soft and less stable feel. On very bumpy tracks with large undulations this is often a good change in comparison to moving the shocks inwards on the tower as it doesn’t hinder the jumping ability as much as a “tower” move.  Outward mounted shock positions on the arm gives the car a more stable feel and helps the car rotate quicker in turns.  This comes at the expense of a car that may not handle the bumpier sections of the track as well.

Rear Shock Locations:

Shocks mounted out towards the ends of the rear shock tower or “outward” will decrease traction and add steering while increasing dampening. Moving the shocks inwards on the tower will again gain “progression” which will increase traction but decrease damping which affects how the car lands off jumps,etc.  In general the smoother the track, the more laid down your shocks might be. If the track surface provides a lot of natural traction you can stand up your shocks more to gain corner speed, etc.

The rear arm location notes essentially mimic the ones in the “Front Shock Location.”

I will add that making ANY of these changes you should always check and adjust your ride height as needed. Another factor often overlooked by new racers is that when changing shock locations you will be changing your droop as well. If you don’t compensate for the shock length as you move then in-out on the arms/towers you may not get the proper adjustment you were looking for. A shock that is mounted further in on the tower/arm will give more droop than that same shock mounted further out on the tower/arm.  So pay attention and check both ride height and droop. If you watch the top pro drivers in any scale while they’re making changes both before and after they’re doing this. They may eye ball the adjustment or get out a pair of dial calipers to measure the shock length, etc.  If your car has droop screws you can adjust overall droop there, but in 1/10 most cars are setup to use internal shock limiters. When you build your shocks you MUST make sure that they’re the same length left to right. While it may not seem like a big deal at the time, being off .5 or 1.0mm in shock length from one side to the other will lead to droop being off from one side or the other. It’s the little things that add up to those missing tenths of a second from the super fast guys and the regular fast guys.

Good Racing!

Randy Pike