Articulation: Pro’s and Con’s

By Axial on Mar 19, 2010

Articulation Pro’s and Con’s for Shaft Driven Crawlers:

There are very few, if any, situations where more suspension travel is better. The more travel you have your rig set-up for, the harder it is to tune. This article is meant to help people better understand suspension travel. I will go over different scenarios that come up during competitions and try to explain what set-up works where and why. I’ve received a lot of questions over the years about suspension geometry and articulation. Most new comers to the RC rock crawling world think that tons of suspension travel (articulation) is key when competing. When, in actuality, limited suspension travel is probably better in almost every situation you encounter during a competition. Plus, having a shorter travel set-up usually means you have a lower center of gravity (CG). Having a lot of articulation usually leads to quite a bit of axle steer as well. Axle steer can make traversing some obstacles very tough because as a tire drops out it’s trying to steer you in a direction you most likely don’t want to be going in.

Steep Climbs:

Probably one of the most common obstacles you’ll see in R/C rock crawling is steep vertical faces. Almost every comp I’ve ever attended has had at least 1 or more really steep climbs thrown in some where. Rig set-up, and tires, will be a big factor in dictating whether you can make these climbs or not. The best suspension set-up for obstacles like this is a short travel suspension that is fairly stiff. Properly set-up suspensions on steep faces will usually walk right up them with little to no drama. Vehicles that have a lot of travel will usually struggle on these types of obstacles though. Front tires will most likely want to lift on steep climbs if your rig is set-up for too much travel. Even if you run a somewhat stiff suspension set-up your rig will still probably want to lift wheels in the air. As soon as your rig starts lifting the front tires you are losing traction and forward bite. Keeping the front tires planted on steep climbs is a key element to making these types of obstacles. A good way to test your set-up is by using a piece of plywood with an abrasive surface on it, like sandpaper. This can be set-up at a given angle just about anywhere to test how steep your rig can climb, and to see how much lift you get out of the front tires. Once you have the plywood obstacle set-up. Try to crawl to the top of the plywood as slowly as you can. Pinning the throttle to see if you can make it doesn’t really tell you what you need to know. A slow controlled ascent will tell you a lot about your rig’s suspension set-up.

Here are a couple pictures of my comp rig climbing a steep face. I recently removed almost all of my front wheel weight just to lighten my rig up a little. There is only a few ounces in each front wheel now. And it will still climb steep faces without lifting tires. Lifting front tires on climbs like this will also probably pull you off your intended line. Keeping all 4 tires planted is the key.




Off Camber:

Another common obstacle seen at most competitive R/C rock crawling comps is off camber situations. Gates are usually set-up on a steep face, and they will most likely require you to drive through them at an odd angle. Having too much travel on obstacles like this can hurt you too. All 4 tires will need to stay in contact with the obstacle for you to successfully negotiate it. Having a front tire lift on these off camber obstacles will pretty much guarantee you a one way ticket to the bottom of the obstacle before you clear the intended gate. Again, a shorter travel set-up will excel in situations like this, as long as the suspension isn’t set-up too soft. A lot of times there is a fine line between a shock set-up being too soft or too stiff. Ideally, you want the suspension to be as stiff as possible without it limiting your shock travel. That is why playing around with different shock pistons, springs and oil is so crucial when dialing a new rig in.

In this situation if my driver’s side tires started to lift, I would probably roll off this ledge. Notice my foam set-up is very soft, maybe even too soft. But, this is my cold weather foam set-up and it was 80 degrees outside when I took these photos.




V-Notches are another fairly common obstacle seen during comps. These obstacles have an entrance that is “V” shaped and that shape usually continues up a crack where the walls are about 90* to each other. These situations require you to keep your rig level as you drive up through. If you fall into the crack with your driver’s side, or passenger side, tires it’s usually tough to get back on line without using dig. Longer travel set-ups on obstacles like this will drop tires way down into the crack. Usually when this happens you are stuck in a position you don’t want to be in, and driving out of the dilemma will be very tough without taking a 10 point reposition penalty or several reverses. A shorter travel set-up will generally work better here, because if you do get off line and drop a tire in, the tire will only drop in so far. At this point you can usually steer into one side of the notch, or the other, to keep yourself level in the obstacle you are trying to clear.

Here you can see you want to keep your rig centered over the “crack” of the V-notch.






Holes are another obstacle you will probably see a lot of in competitions. Gates are usually set-up so that one front tire and/or one rear tire drops into a hole or crack bigger then most 2.2 tires. Having too much articulation can hurt on obstacles like this too. A short travel set-up will be less likely to get caught in holes, because most times you can “float” a tire over a hole. A rig with a lot of travel will probably drop one tire completely into the hole, making it difficult to stay on line and clean the gate you are working on. Most times when a tire is swallowed up by a hole you will be forced off line. If a front tire gets caught the rear end usually walks out to one side as the captured tire tries to free itself. If a rear tire gets caught the front usually gets pushed or pulled off line as well. Having a suspension set-up that can float over holes will be a lot easier to drive in and out of situations like this.

At the end of the V-notch from the last paragraph was a hole that worked for this example. In these pictures you can see my front tire is floating over said hole on the passenger side, instead of dropping into it and possibly sucking my rig down into the crack with it. Having a well balanced rig in these situations will help too. If you run a ton of weight up front and none in the rear you may still flop down into the hole.


If that tire drops into this hole the outcome will be very tough to drive out of.

Once that tire drops, you will be looking at a situation like this. Easy to see that it will be harder to drive out of than the first picture.


Obviously, obstacles and terrain will vary quite a bit, as do rig set-ups and driving styles. So, not all of these scenarios I’ve brought up will be cut and dry. But, this should serve as a good basis for tuning a rig to have a little shorter travel than the average “new-comer “thinks they need. I personally build my comp crawlers to flex the height of the tire I’m running, and I always set the front suspension up a little softer then the rear. There are many factors in determining how capable a rig will be, like suspension geometry, ride height, weight distribution, tire choice, foam selection, shock tuning, etc. And there is no magic formula for building a crawler that has the potential to win competitions on your first try. But, playing around with different set-ups will help you learn what works for you, your vehicle and your terrain. Practice driving your rig as much as possible, and have fun while you do. Don’t be afraid to show up at a local comp to check it out and compete. 99% of the people I’ve met during R/C crawl comps are some of the nicest people I have ever met.


  1. Default_avatar autry Posted on 2010-03-23 17:42:07

    thats good to know because my ax10 rtr ive spent $300 dollers on the little thing and trying to get as much articulation on it thanks.

  2. Default_avatar Jake Posted on 2010-03-25 19:10:01

    More like this PLEASE! Also, how about a set-up sheet with your current setup all listed out?

    Thanks Bender!


  3. Default_avatar Orin Posted on 2010-03-26 03:56:31

    Thanks for the heads up. i found this article very informative! I have reduced my suspension recently and now i am playing arround with front/rear shock weight. The point of having a tyre height of articulation, i find most important.

  4. Default_avatar Chris Posted on 2010-04-01 19:54:31

    This would explain why my SCX-10 can run circles around my AX-10 in a boulder field… it makes sense too. GREAT article!

  5. Default_avatar Casey Posted on 2010-04-06 13:53:01

    OK so here is the dumb newb question. What do you need to change, adjust or replace on your rig to help lessen your wheel travel? Do I want to adjust my shocks so the coil spring on the outside of the shocks are compressed as much as possible?

  6. Default_avatar Bender Posted on 2010-04-06 14:25:03

    Thanks. I will try and do a blog post on my most recent SWX set-up soon too.

  7. Default_avatar Bender Posted on 2010-04-06 14:34:10

    There are a few ways to shorten up your articulation. One is put a limiter inside your shock body underneath the piston, like a short piece of nitro fuel line. This will shorten the shock up, and give you less travel. But, it will also lower your ride height. If you shorten the shocks up a lot, you may have to switch out to softer/shorter springs too. If you are happy with your ride height and shock performance and you just want less travel, you can just install a “limiter” outside the shock body to shorten the stroke of the shock. Another way to limit travel is by just standing the shocks up more vertically, which may also require softer springs/shock oil. This can be tough to do with some chassis’ though. Another option is to switch out your current shocks for something shorter altogether, like a scale shock for instance.

  8. Default_avatar Siddharth Rane Posted on 2010-05-01 03:34:45

    Thanks a lot. Very well explained. will be changing my setup today itself.


  9. Default_avatar jayden Posted on 2010-07-26 20:55:11

    im getting a ax10 scorpion rock racer rtr is this a good type or what please comment!!

  10. Default_avatar jayden Posted on 2010-07-26 20:56:27

    im getting a ax10 scorpion rock racer rtr is this a good type

  11. Default_avatar Bender Posted on 2010-07-28 07:18:39

    The RTR is great platform to start out with. It has decent wheel speed out of the package. But, can be a decent crawler too, when you install the front locker.

  12. Default_avatar autry hailey Posted on 2010-09-17 17:47:24

    sry for the late comment lol, but I changed my ax10 rtr into a comp crawler and now I turned it into a scaler but the ax10 rtr is a good truck but if you want a really good crawler i would go with the rtc as far a ready to run goes but the ax10 kit would be better for a seriouse rock crawler and even the xr-10 would be awsome.

  13. Default_avatar sTEPHEN yAKKEY Posted on 2010-11-25 11:25:10



  14. Default_avatar Bender Posted on 2010-11-29 08:35:59

    The SCX10 is a very capable rig, you would be surprised by where that truck will go. If you aren’t looking to compete, then I would go with the SCX10.

  15. Default_avatar painter 11 Posted on 2011-01-20 17:47:38

    Took me time to read all the comments, but I really enjoyed the article. It proved to be Very helpful to me and I am sure to all the commenters here! It’s always nice when you can not only be informed, but also entertained! I’m sure you had fun writing this article.

  16. Default_avatar Unregosesesee Posted on 2011-01-20 18:01:25

    Very good post! Your post could not be more appreciated.

  17. Default_avatar fight night round 4 Posted on 2011-01-22 00:26:32

    Thank you for taking the time to make that clearer.

  18. Default_avatar foxit reader Posted on 2011-01-22 00:31:22

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  19. Default_avatar tagged home Posted on 2011-01-22 16:29:08

    That is very helpful. It presented me a number of ideas and I’ll be placing them on my blog eventually. I’m bookmarking your website and I’ll be back. Thank you again!

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