RC Suspension System Check – Make your suspension work better
This month’s RC Beginner Series tackles the suspension system. The first thing that you think about when you say “suspension” is shocks, but unless all your suspension components are working correctly, the shocks cannot do their job. So, in this blog we are going to talk about all of the suspension components and how to free up your suspension to allow your shocks to perform at their best.
RTR vs KIT building
When building a KIT, it’s easy to check all of the suspension components for free travel and no binding. RTR’s (Ready to Runs) are quickly assembled and can have issues right off the assembly line, like you’ll see later in this blog.
Get your RC ready to check its suspension
- Remove the body and wheels/tires from your RC
- Remove all four shocks from your RC – Typically there’s a top mount and a bottom mount. Be sure to either take a photo or write down what position your two mount are in, as many RC’s have multiple shock mounting positions and changing it can alter the way your RC handles.
Check your suspension travel
- Now that the shocks are off you should have full uninterrupted travel of your A-Arms.
- Give each A-Arms a drop test. Each arm should be able to “fall” under it’s own weight while the shock is off.
- Test all four A-Arms
Like my Team Associated ProRally, I had some binding on my front A-Arms. Here’s the typical areas to check on a standard knuckle/C-hub system:
- Inner hinge pin – This is the hinge pin that sits closest to the center of the RC attaching the inside of the A-Arm to the bulkhead. It will typically be the longest pin.
- Outer hinge pin – This is the hinge pin that sits closest to the wheel attaching the end of the A-Arm to the C hub and knuckle.
- Bent Hinge Pins: Yes, those steel hinge pins can bend. A quick check on a flat surface while rolling the hinge pin will determine if it’s bent.
- Turnbuckles – Front suspension systems will have two (camber and steering) and rear will have just the one on each side (camber) These should wiggle freely with no binding. Sometimes leveling the front A-Arm to a parallel position to the ground will show a freer steering turnbuckle.
Fixing your binding
- A-Arm reaming – sometimes A-Arms and hinge pins aren’t perfectly mated and the Arms need to be reamed to have a perfect bind free fit. Arm reamers are available on a multitude of sizes (typically 3.0, 3.5 and 4.0mm for 1/10th and 1/8th scales)
- Part Replacement – Hinge pins should always be replaced and not re-bent. The odds of getting them perfect again are slim and will lead to additional wear on the rest of the suspension system. Typical hinge pin replacement kits (all pins for the RC) are under $10.
- Turnbuckles – As seen with my ProRally, I had additional binding on the steering turnbuckles that didn’t allow the suspension to fall under its own weight. Under further inspection, the wrong size ball stud was used for those ball cups, so an upgrade to a captured rod end solved the issue and was only a $5 upgrade.
Can your suspension be too loose?
Yes, any type of excessive wobble, wiggle, etc can deter the performance of your suspension. While the shocks are off, you can check for this as well. Typically replacement of the A-Arms, rod ends / ball cups are needed to improve this issue.
I hope this quick blog has helped your RC and given you an even better driving experience! Have fun out there RCing!
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The Team Associated ProRally 1/10th scale Brushless RTR Rally Car is available for a limited time at a smokin’ low price here:
RC Beginner Series Topics
Jan. – Tools needed for your new RTR/Using your Owners Manual
Feb. – Battery Safety/Lipo rules/Battery Choices
Mar. – Ride Height Adjustment/Shock Collars
Apr. – Trims and Dual Rate on your Radio
May – Clean Your RC – Compressed Air
Jun. – Changing your Pinion/Gear Mesh
July – Adjusting Body Height
Aug. – Adjusting Turnbuckles – Camber/Toe
Sept. – Inspecting Bearings/Free Driveline
Oct. – Adjusting Slipper Clutch
Nov. – Inspecting Suspension/Free Suspension
Dec. – Shock positions
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