In this installment of Suspension 101 we are reviewing the basics of ride height and camber and how those settings affect your RC vehicle’s performance. These are two of the most basic suspension adjustments, yet they can make a big impact on the overall feel of your vehicle. There can be a lot of science and tuning behind these adjustments, but we aim to keep this article as simple as we can for the sake of ease of reading and understanding the fundamentals. For more in-depth tuning information on the specifics of your own vehicle, it’s always helpful to consult the manufacturer along with model-specific groups on forums and social media. With that being said, let’s get to it.
We will need some specialized measurement tools for proper settings adjustment. Along with these tools we will also need a decent workspace. This can be an area in your garage, hobby room, a portable table, or a bench at your local racetrack or hobby shop. It also helps to have a perfectly flat board or plank to work on, generally known as a “setup board.”
We’ll need a small ruler or a set of precision calipers, a reliable camber gauge, some small wrenches for suspension link adjustments, and a properly sized ride height gauge. As for exactly which size ride height gauge, we will get into that a little later.
First off, let’s start by discussing ride height. Ride height is simply the measurement between the ground and your vehicle’s chassis. It is used as the main way to adjust your vehicle’s center of gravity and affects handling through chassis roll. Chassis roll is what happens when the weight of the vehicle shifts toward one side or the other, most often in turns.
The amount of chassis roll needed depends on the type of vehicle, the use of the vehicle, and the surface grip of where the vehicle is being used. If you are out bashing your favorite monster truck, you most likely won’t need to care as much about chassis roll as you would running a race vehicle at a racetrack. Although ride height and chassis roll might not play as big a roll for basher vehicles, I am very much in favor of adjusting your basher’s ride height for different types of terrain since it can still make a noticeable difference in handling performance.
The main reason for adjusting ride height is to raise or lower the vehicle’s center of gravity to change its chassis roll, and in turn its overall response and handling. The height of the chassis should be adjusted based on the conditions and grip level of the running surface. Plainly speaking, if you are running on a smooth, flat surface with lots of grip, then a lower ride height is usually favorable. On the flip side, if you are running the vehicle on rough terrain with lots of ruts and bumps, then a higher ride height will most likely be ideal.
MEASURING AND ADJUSTING RIDE HEIGHT
To measure ride height properly we need a nice, flat surface to work on. As mentioned above, this can either be a flat worktable or a dedicated setup board designed for measurement purposes. For off-road vehicles you’ll need to drop the vehicle onto the table. What I mean by this is literally drop the vehicle from about 6 inches above the work surface, letting it fall freely into place. This will ensure the suspension settles into its natural resting point.
For on-road vehicles, simply place it on the table instead, rolling it back and forth and then pressing down on the chassis a couple of times to settle the suspension. Once the vehicle suspension is settled, take your ride height gauge and measure the height of the flattest, lowest point of the front and rear of the chassis. This is usually the lowest point on the bottom of the chassis, excluding any kind of special bumpers or guards on the vehicle.
Adjusting ride height can be achieved using one of two methods, both of which alter the placement of the shock spring. The first and most common method is to use threaded shock collars. To lower the vehicle simply raise the shock collar, and to raise the vehicle simply lower the collar. Easy, right? It’s a good idea to match the shock collar positions side-to-side for consistency using a small ruler or set of calipers. If your vehicle doesn’t have threaded shock collars, then we will need to employ method #2 using spring spacers. Ideally your vehicle should have optional spacers, known as pre-load clips, that were included with the kit. Most vehicles with non-threaded shocks include several differently sized clips to allow for multiple height adjustments. Just like with the threaded collars, add or remove pre-load clips as needed to reach the desired spring height.
What height should you set your vehicle to? Out of the box the vehicle should be at its “baseline” setting, so that will be a good starting point, regardless of the type of vehicle you have. How much you adjust one way or the other will depend on where you’re using it. Ideally, you’ll want to make small adjustments until you reach the perfect height. The “perfect” height just means when the car starts to handle better on the current running surface. How far you go with the adjustment overall is up to you.
As a real-world example, if I’m taking an off-road vehicle out to some rough terrain with lots of jumps, I’ll usually raise it 2 to 3 millimeters from its baseline setting. In a similar fashion, if I’m taking that same vehicle to a parking lot or a skatepark I’ll generally lower the vehicle by a few millimeters to improve handling. A couple millimeters of ride height adjustment can go a long way toward improving the vehicle’s capabilities, whether that be better landings of big jumps or smoother handling during parking lot sessions.
After we have ride height dialed in, we can turn our attention to camber. Camber is the vertical angle of the wheels and is measured in degrees of angle from where the face of the wheel meets the ground. A negative camber angle leans inward toward the vehicle, while a positive camber angle leans outward away from the vehicle. Additionally, a zero (0) degree camber angle is perfectly upright with no inclination one way or the other. Camber angle can be viewed while looking straight on at the vehicle when it’s placed on a flat surface. It is best measured with a specialized tool called a camber gauge.
Camber angle affects the amount of tire that contacts the ground, known as the tire’s “contact patch.” Camber also dynamically changes as the vehicle moves (from chassis roll), which in turn dynamically changes each tire’s contact patch and ultimately affects the vehicle’s overall grip. The amount of camber change will vary depending on the vehicle’s design, but generally speaking as the vehicle moves to one side that side biases toward a more positive camber angle. Because of this it’s best to avoid running positive camber angles on any of the wheels.
MEASURING AND ADJUSTING CAMBER
First off, place the vehicle on a flat surface, just like the one we used for adjusting ride height. You will want to set your ride height first in order to get a proper measurement for camber. Once the vehicle is on the work surface, place your camber gauge as close to the center face of the wheel as possible. The gauge should be perpendicular to the wheel and, when viewed from the front, should display the degree measurements on the gauge. It’s best to dial in the amount of angle you want on the gauge first, then place it against the wheel for comparison. If there is a gap at the top or bottom of the gauge, you will need to adjust accordingly.
To adjust camber, we will need to shorten or lengthen the camber links. These are the uppermost suspension links at the front and rear of the vehicle. If you want to dial in some negative camber, shorten the links. If you require a more positive setting, lengthen the links. It’s also best to make sure the links are a consistent measurement on both sides, again using calipers or a small ruler. Once the links have been adjusted, measure again with the camber gauge, making more adjustments as necessary to meet the desired angle.
As for a baseline camber setting, 1 to 2 degrees of negative camber at the front is a good starting point on most vehicles, as this accommodates for typical camber changes while turning and driving. Zero degrees of camber at the rear is best for straight line traction, but 1 or 2 degrees of negative camber can be dialed in if the backend of the vehicle is breaking loose on turns. This is something to adjust to taste and is really based on the type of vehicle and terrain you’re on, but it’s an overall good starting point regardless.
That wraps Suspension 101 on Ride Height and Camber. These are two very basic measurements that can have a very complex impact on your vehicle’s handling characteristics, so be sure to take your time and make small adjustments until you reach that perfect setting. I hope you found this guide helpful; we will be back with more Suspension 101 articles in the future. As always, thanks for reading. I’ll catch you in the next one.
Gauge Size Matters
Proper ride height measurement requires the proper size of ride height gauge. These gauges come in many different shapes and sizes, and the one you need will depend which RC vehicle you have. As an example, most 1/10-scale off-road vehicles will use a gauge that ranges from 15mm to 30mm. For 1/10 on-road vehicles you will want to use a gauge that ranges from 2mm to 10mm. For larger vehicles, such as 1/8-scale buggies and truggies, you’ll want to use a gauge that ranges from 30mm to 45mm.
Text and Images by: Lauren Short