General shock set up knowledge

[Minoa]

Hello, community. I'm looking for some general shock knowledge, somewhere I can start with in my first real attempt at setting up shocks.

First off, let me say I come from a bashing background. I never gave them much concern. As long as my truck would go straight, take some jumps here and there, and they had oil in them, I figured they were doing their job.

Second, I'm not looking for info about a specific platform or chassis. These questions are more about how different positionings affect the shock, regardless of the platform. Maybe even how 1:1 shocks behave.

Let's start with the front axle. How does mounting the shock wider on the axle affect handling? Obviously, mounting the shocks closer together on the axle would have the opposite effect? Or not? How about mounting them more vertical than horizontal? And again, would mounting them more horizontal than vertical have the opposite effect?

How about the rear axle? Would the shock mounting position affect the rear axle in the same way as the front? Any noticable differences?

Are these different shock positions more about getting ground clearance or just a personal preference with the look of the truck/body?

Anything I miss? Any insight/tips for a noob is appreciated.

 

[Minoa]

I guess I forgot to even mention anything about how the mounting of the shocks on the chassis affects things...

 

[JatoTheRipper]

There's a ton of info out there on the internet about RC suspension and 1:1 suspension which often applies to scale crawlers. Some of that info is even on this site. Honestly, shock setup is much less important on crawlers than it is with go-fast rigs. I'm sure there will be people that disagree with that, but with crawlers you can be close and it's good enough for most of us.

 

[Topher Builds]

So without getting too technical, mostly because it’s beyond my knowledge, I’ll try to give some insight from my experience.

Tuning your shocks isn’t so much about clearance however it can help with general stability, incline performance, and sidehilling.

I won’t get into what oils or which shocks or which springs to use or how much droop as that’s all personal preference, all of these things play together and impact each other so trial and error is needed to get your ideal set up.

Rear shocks you’ll want to have angled towards the front of the truck. This will push the truck forward instead of up and backwards on an incline and will help with back flipping.

Having the lower shock mount wider than the top can help with sidehilling. This also impacts how much force is needed to compress the shock so spring and oil tuning is needed here.

Softer springs up front. Firmer in the rear.

Pre-load has material impact on performance as well. Your left and right preload should be relatively similar while you may have more preload in either the front or the rear depending on your springs. If you play with the preload on an incline, keep trying the same spot over and over while adjusting to see what works best. Setting it so the rear end stands up and keeps the truck pointing forward while the front end compresses more will likely yield decent results.

Again, all trucks, shocks, springs, oils, and terrains are different so trial and error is your friend. With all this being said, I’ve spent hours and hours tuning shocks before and some guy with an OG SCX10 with short shocks and no flex will crawl right up the wall, so like Jato said it really only matters so much with a crawler.

As you crawl closely watch the suspension and what it’s making the truck do, this will help give you an idea on what areas to focus on first.

 

[lonleycreeper]

Too much flex is a bad thing...

I am one of those guys running near stock Scx10's and find adding weight and travel usually hinders performance.

Pat has a couple good points, but a couple I disagree with.

Really the goal of a crawler is to keep the tires in contact with the ground, and the faster you go, the more critical it becomes.

As a general rule the further you lay down a Coilover, the less dampening and spring rate it has. On the other hand you gain more travel.

 

[Topher Builds]

Too much flex is a bad thing...

I am one of those guys running near stock Scx10's and find adding weight and travel usually hinders performance.

Pat has a couple good points, but a couple I disagree with.

Really the goal of a crawler is to keep the tires in contact with the ground, and the faster you go, the more critical it becomes.

As a general rule the further you lay down a Coilover, the less dampening and spring rate it has. On the other hand you gain more travel.

I’m new to this stuff too and would appreciate contradicting perspectives if you wouldn’t mind elaborating where you disagreed. All for good discourse "thumbsup"

 

[lonleycreeper]

I am picking nits here...

I come from a racing background Rc10 era...

I find weight placement and link geometry a much more critical aspect to tuning a crawler.

Shock length and preload are all about clearance and ride height. Springs and oil dampening for control and bounciness...
Out boarding shocks...

I find if you mount the lower shock wider than the top you loose just a bit of side hill stability due to the loss of spring rate and dampening. Now if you compensate for it, it can be beneficial.

 

[Topher Builds]

I am picking nits here...

I come from a racing background Rc10 era...

I find weight placement and link geometry a much more critical aspect to tuning a crawler.

Shock length and preload are all about clearance and ride height. Springs and oil dampening for control and bounciness...
Out boarding shocks...

I find if you mount the lower shock wider than the top you loose just a bit of side hill stability due to the loss of spring rate and dampening. Now if you compensate for it, it can be beneficial.

Can’t disagree with that. I appreciate it.

 

[oldmancrawl]

Softer springs up front. Firmer in the rear

What's the reason for that?

Same deal even if the rear of the vehicle is quite a bit lighter weight?


this stuff is new to me.

 

[CODYBOY]

What's the reason for that?

Same deal even if the rear of the vehicle is quite a bit lighter weight?


this stuff is new to me.

When your making a climb the weight of your truck will want to shift to the rear. By having a little stiffer rear it will compensate for the weight transfer. This helps keep truck from flipping over backwards quite as easy. "thumbsup"
Ernie

 

[wyd]

When your making a climb the weight of your truck will want to shift to the rear. By having a little stiffer rear it will compensate for the weight transfer. This helps keep truck from flipping over backwards quite as easy. "thumbsup"
Ernie

I come from racing 1/10th off road and all springs really do is set the right height and teh shock oils do the dampening. Is this the same or crawling that the springs just set ride height and oils set your dampening rate? Right now I have heavier springs on the front do to the extra weight has on the front end and was easier to get the ride height and droop setup where I wanted it without having to crank down on the spring collars so far in the front like I do if I use softer springs.

 

[CODYBOY]

I come from racing 1/10th off road and all springs really do is set the right height and teh shock oils do the dampening. Is this the same or crawling that the springs just set ride height and oils set your dampening rate? Right now I have heavier springs on the front do to the extra weight has on the front end and was easier to get the ride height and droop setup where I wanted it without having to crank down on the spring collars so far in the front like I do if I use softer springs.

I think it all comes down to personal preference and driving style. I think your right on with how spring and oil rates/weight plays into tuning a off road rig. IMO the effects they have in scale crawling has a lot less play into handling. We aren't trying to clear those triples or driving hard into that turn.

How it does come into play is in ascending, climbing and side hilling and how they help with COG. For me I use spring and adjustment collars to tune for all of the above. I like having my rear a little stiffer when climbing to help with keeping the rear a little more planted going over a ledge or vertical rock. If I want to adjust ride height I use the collars. I run my rigs with I/2 to 2/3 droop. Like I said personal preference and driving style, I sure there are guys out there reading this and shaking their head and say "NO WAY"

Drive on,
Ernie

 

[wyd]

I think it all comes down to personal preference and driving style. I think your right on with how spring and oil rates/weight plays into tuning a off road rig. IMO the effects they have in scale crawling has a lot less play into handling. We aren't trying to clear those triples or driving hard into that turn.

How it does come into play is in ascending, climbing and side hilling and how they help with COG. For me I use spring and adjustment collars to tune for all of the above. I like having my rear a little stiffer when climbing to help with keeping the rear a little more planted going over a ledge or vertical rock. If I want to adjust ride height I use the collars. I run my rigs with I/2 to 2/3 droop. Like I said personal preference and driving style, I sure there are guys out there reading this and shaking their head and say "NO WAY"

Drive on,
Ernie

Sounds good to me. I'm going to try a little stiffer rear for when I go trailing tomorrow and see,how it works. Normally it does well except for this indoor indoor place that I test at. Its pretty blown out and not maintained that much.

 

[MAC FAB]

Wide on the axle vs narrow, look at pick up trucks. They are wide now F 150 years back was the first, to reduce the leverage on the springrate with "flex". In the go fast world full size, you are looking for a 90 degree angle in the shock to the arm its attached to in full bump to have a truely progressive rate. Look a class 5 unlimited bug front ends to see this in an interesting application. Soft shocks keep tires planted at the cost of body roll. I am new to the crawling circle as well, and am toying with my shocks. It is becoming evident to me that bypass piston will be the ticket, I need to slow compression with my current tune. Just like the go fast world, I also firmly believe you need to shoot video to be able to assess what you rig is doing and come up with a plan to fix any shortcomings.

 

[JDM74]

I also firmly believe you need to shoot video to be able to assess what you rig is doing and come up with a plan to fix any shortcomings.

This. I shot my bomber with my iPhone in slow-mo doing a simple drop test to tune my shocks. I then took it for a test run to see how it handled. My bomber is more of a go-fast build though. I think video would still apply to the crawler world and you probably wouldn't need to use slo-mo.

 

[Topher Builds]

I think it all comes down to personal preference and driving style. I think your right on with how spring and oil rates/weight plays into tuning a off road rig. IMO the effects they have in scale crawling has a lot less play into handling. We aren't trying to clear those triples or driving hard into that turn.

How it does come into play is in ascending, climbing and side hilling and how they help with COG. For me I use spring and adjustment collars to tune for all of the above. I like having my rear a little stiffer when climbing to help with keeping the rear a little more planted going over a ledge or vertical rock. If I want to adjust ride height I use the collars. I run my rigs with I/2 to 2/3 droop. Like I said personal preference and driving style, I sure there are guys out there reading this and shaking their head and say "NO WAY"

Drive on,
Ernie

Well said Ernie "thumbsup"

I have a similar approach. Because of this preference for climbing my trucks sit lower in front than in back. Exhibit A below (sorry for low quality, cropped from a much bigger picture)

 

[Duuuuuuuude]

Setting a rig up to climb is great if all you do is climb. I prefer a more rounded approach.

Spring rate sets the ride height. I like mine near level with near equal movement in each direction. Each end of the rig will require different amounts of spring rate or preload. Use what you've got.

Shock oil dampens spring bounce. Pick the rig up a few inches off of the bench or table and drop it. A balanced setup will allow the front and the back to compress and rebound at the same rate. Thicker oil = more dampening. Thinner oil = less dampening.

Shock angle effects spring and dampening rate, and the amount of suspension travel. Straight up and down gives you less travel with the most consistent rate. Angled in or front/back gives you more travel with a decreasing rate. Keep in mind that maximum travel is not always ideal, nor is having a consistent rate.

Also keep in mind that each rig will be different from another, sometimes slightly, sometimes wildly. The time you spend finding what works best for yours will put you miles ahead of the person that simply copies what someone else is doing.

Don't be afraid to make wild swings in adjustments to see what they do, but don't make more than one at a time until you understand what is going on.

Lastly, suspension tech is a deep subject. There are a ton of different approaches. Take your time, and don't worry if you get lost doing it. If it were easy we'd all be pro's.

 

[MAC FAB]

Document your changes and results as well, better working, great. If it sucks, you know where you came from.

 

[new2rocks]

There’s some good info in here from Duuuuuude, Codyboy and others. I’ll drill down a bit on oil and suspension travel. Over time, I’ve come to prefer heavier dampening on most of my crawlers and trail rigs. I find that when going slow, the suspension doesn’t need to react as quickly, and slower suspension movements (both compression and rebound) add stability when you’re approaching limits or tackling very uneven terrain (e.g., side hilling). Depending on the particular shock, I’ll often use diff fluid (3k or 1k) to get to a place that I like.

As a few people have noted, suspension travel (aka flex) is highly overrated. With fully locked diffs front and rear, it’s okay to have a wheel off the ground, and too much travel can make a truck unstable, especially in the rear. Most of the popular truck platforms have plenty of suspension travel (some too much). Very few suffer from too little travel. So separate and apart from using springs to fine-tune ride height, I will sometimes run shorter than stock shocks to lower the center of gravity without having to soften springs too much and increase stability without having to overdampen suspension movements.

But the best advice is try out different setups and see what you like. It’s also good to get out to events and casual get-togethers to see other setups in action. I’ve learned a ton that way, as well. “thumbsup”

 

[wyd]

I agree that some great info is here. Fun to read over everyone's ideas and thinking on the suspension.

I been running my truck with softer dampening for a few weeks so now when I go out again this weekend I'm going to try a little heavier dampening of the shocks to see how my truck feels. I have heavier springs in the front so I didn't have to run the spring retainers down so far as I like to keep mine equal front to rear but just switch out springs. Just never was one to run my collars really far down.

Test it out and if I don't like it I can always change back. Think I will also run some limiters on the outside of my shocks as well just to see how it feels.