| |

Tuning With Shock Mounting Location

Sometimes it’s the simple stuff that can be the most confusing. Shock mounting locations are a great example. So is dating, but we don’t cover that here. Getting back to shocks, there are generally two camps when it comes to this subject–those who think they know all there is to know and those who don’t get it and thus don’t mess with it. Whether you are in the know or need to learn, keep reading and make sure you’re using one of the best tuning adjustments correctly.

PHYSICS 101
Remember those science lessons in school about simple machines such as ramps, pulleys and levers? Your teacher probably explained how these devices provide a mechanical advantage. Well, the typical suspension arm works just like a lever and that fact is the whole key to tuning with shock mounting location. Here’s the deal: when a lock is mounted further outboard on a lower suspension arm, the arm has less of a mechanical advantage on the shock. End result? The shock feels stiffer compared to it being mounted more inboard. It, of course, works just the opposite if you move the lower mount in. Doing so increases the mechanical advantage the arm has over the shock and the shock setup feels softer.

ABOUT RIDE HEIGHT
Many people who start out bashing, use the lower shock mount position to change ride height. Sometimes they do this to gain more ground clearance for rough terrain, but they also often do it so they don’t bottom out when landing big air. Ironically as they move the lower shock mount in and push the arm down at more of an angle, they are softening the shock setup. So, they’ve gained some room before the chassis slaps the ground, but they’ve just made it easier to bottom because the shocks are now softer. Those guys need to add stiffer springs to compensate.

In racing, we don’t want to have our ride height impacted by unrelated tuning adjustments. So, if you change the lower arm position, immediately check your ride height. Most of the time, a small spring preload adjustment will return the ride height to the desired setting.

SHOCK ANGLE
Most people will be able to feel the difference moving the lower position makes. Moving the upper position is simply a little more subtle. The upper position is usually changed to correct the shock angle after a lower position has been changed. That is not to say the upper position can’t be changed independently. It, of course, can and leads us to what shock angle does. If the lower position mostly influences the overall rate (firmness or softness) of the shock, the angle mostly influences the progressiveness of the shock–how the shock changes as it’s compressed. The more the top of a shock is leaned in, the stiffer the shock will feel as it’s compressed. A shock that is positioned fairly vertical, will be linear (i.e. feel the same as it’s compressed).

USING SHOCK MOUNTING POSITION
Lower Position Front Arms
Outer Holes
> Firmer feel
> Stable handling
> Less body roll
> Less steering
Inner Holes
> Softer feel
> More front traction/steering
> Smoother over rough surfaces

Lower Position Rear Arms
Outer Holes
> Firmer feel
> Stable handling
> Less body roll
Inner Holes
> Softer feel
> Good rut and bump handling
> Less side grip

Upper Position Front Tower
Outer Holes
> Less nose dive off jumps
Inner Holes
> More initial steering entering corners

Upper Position Rear Tower
Outer Holes
> Less traction during cornering
Inner Holes
> More traction during cornering

Similar Posts

13 Comments

  1. Sweet lil reference guide for when your trying to dial your truck in on the track…may just print this out and stuff it in my toolbox. Thanks!

  2. Hey Matt, I’ve shopping for a new set of shocks for my SCT, and was wondering if you’ve had any experience with Gmade piggy shocks, or more importantly your opinion on piggy back shocks in general. Thanks in advance, Mike.

  3. Thanks matt,
    This will be posted above my workbench in my race trailer
    I raced a lot in the early 90’s with oval cars and got back into racing last summer.

    I currently have a Losi scte w/mip upgraded chassis this thing rocks lots of wins with it. A Losi TRL 22 SCT I have had it about 2 months A kyosho Truggy w/novorrsi engine 3 wins with that one.

    I cant believe the difference in two wheel and four wheel drive SCT’S I finally figured out thru trial and error you need some weight up front on a tlr22 sct to make in turn in good once I did that a lot of my problems went away and finished 2ed on my third outing with it. I got to learn more about shock setup and this will really help.

    Thanks Again,
    Steve Gordon (Statham GA.)

  4. This is exactly the article I was looking for. After a couple of hours searching on the internet, trying to figure out proper wording and what not, I came across this 🙂 I own a sc10 4×4 same as pictured and I was always mounting my shocks in the different holes but really did not know what the benefits of each were. Now I do. Thanks for the article.

  5. I like you writing style for teaching r/c tuning aspects. I would like to add that as you change shock locations you alter the car’s ride frequency. Your ride frequency changes with spring rate, shock location, kick up or anti-squat changes you make while tuning. Also with the change of the shock angle that occurs during suspension travel. The more laid over the shock is the more progressively weaker the shock gets as it is compressed.

    Keep up the good work

Leave a Reply

Your email address will not be published.