Getting Your Hobby Stock Chassis Right
Most people overcomplicate chassis setup for Hobby Stock racing. I have seen too many builders spend weekends agonizing over 0.5mm changes in toe when they should just be checking their ride height and making sure the truck isn't bottoming out on the main straight. The first version of my Hobby Stock Chassis Setup Manual was basically a collection of notes I threw together after a season of beating up a TC5 on clay tracks, and it turned into something more useful than I expected. Here is how I approach it now.
Start With Ride Height Before Anything Else
This is the foundation. Everything else cascades from here. For a typical 1/10 scale 2WD buggy in the Hobby Stock class, you want roughly 13mm to 15mm of ride height at the front and 14mm to 16mm at the rear when the car is sitting on its tires with the body on and the battery installed. Weight should be distributed so the rear is slightly higher than the front by about 1mm to 2mm. If your rear is lower, the car will want to step out on exit. If the front is too low, you will lose steering response and probably scrape through the corners. I ran into a problem one race day at a local clay facility where my car felt completely dead in the corners. No amount of camber or toe adjustment fixed it. Turns out the front suspension arms were flexing under load because I had used standard polymer arms instead of the thicker metal ones, and the ride height was actually sagging down to 11mm under weight transfer. Swapping to stiffened arms and rechecking ride height brought the car back into the 14mm ballpark and the handling improved immediately. It took about five minutes to diagnose once I stopped guessing.
Camber and Toe Are Not Free Speed
Beginners tend to crank in as much positive camber as they can legally fit and then add toe-in front and rear hoping for grip. This is backwards thinking. On a clay surface with a medium-compound tire, too much front camber starves the tire of contact patch on corner entry and makes the car feel twitchy. My starting point for a mid-moisture clay track is usually -1.5 to -2 degrees front camber and -1 degree rear camber. The rear needs less negative camber because it is following a different trajectory through the corner. Toe settings are where most people waste parts. Too much toe-in front makes the car nervous on roll. Too much toe-out makes it lazy into the corner. For a standard Hobby Stock setup on clay, I run about 0.5 degrees of toe-in front and 0 degrees to 0.25 degrees of toe-out rear. This is not a universal rule. It depends on your track surface, tire choice, and how hard you are driving. The point is that you pick a baseline and measure what changes, not just guess.
Get the Full Details
Ackermann Geometry Matters More Than You Think
Most Hobby Stock chassis come with Ackermann plates that let you choose between racing Ackermann and reverse Ackermann. Racing Ackermann angles the inside wheel more than the outside wheel during a turn, which is generally what you want for high-speed cornering on loose surfaces. Reverse Ackermann does the opposite and is sometimes used on very tight, low-speed indoor tracks. I switched my front pickup points to give more Ackermann and noticed the car planted better on corner exit without any other changes. That said, if you are running a very stiff chassis with minimal compliance, too much Ackermann can make the front end jump off the ground in the middle of a corner. This is a real issue on rough clay whoops sections. You do not need an expensive shock tool to set damping. A simple shock stand and a ruler will get you 90 percent of the way there. The common approach is to measure how much the shock compresses under a known weight. For Hobby Stock, I usually start with 300-500g of preload on the front shocks and 400-600g on the rear. The exact numbers depend on spring rate, which is why I keep a spare set of springs around in 50g increments. If your car is jumping over bumps, you probably need stiffer springs or more damping, not softer ones as some people assume. Oil viscosity is another area where builders waste money. 30-weight silicone oil is fine for cooler weather and medium traction. 40-weight or 50-weight for hot, slick conditions. Going beyond 50-weight rarely helps because the valving on stock shocks is not designed for it. You just get harsh compression without meaningful grip gains. I stopped buying oils above 50-weight about three years ago after a friend showed me data from his shock dyno session that proved it.
What the Setup Manual Actually Covers
My current Hobby Stock Chassis Setup Manual includes step-by-step measurements for ride height, camber, toe, Ackermann, and shock settings across different track types. It covers what to change when the car is plowing, when it is stepping out on exit, and when it feels loose on corner entry. There are also sections on differential setup, gear ratios, and tire selection for both clay and carpet surfaces. I update it every season based on new components and track conditions I encounter. The manual is available for download from the build thread I maintain. You will find a link in my forum signature. It is free and there is no account required to grab it. I do not accept donations or Patreon requests either, so ignore anyone claiming to sell it.
When Setup Stops Helping
No chassis setup will fix a poorly maintained drivetrain. If your differential is worn, your gears are stripped, or your bell crank is sloppy, you will chase setup changes forever and never find the answer. I spent an entire afternoon adjusting toe and camber on a car that turned out to have a bent rear hub. The hub was only off by maybe 0.3mm but it made the rear step out unpredictably through every corner. Always check the basics before you tear into the geometry. There is also a limit to how much you can tune around a bad tire choice. Running a hard compound tire on a low-traction track and hoping setup will compensate is not realistic. The tire is the first variable you should get right. Everything else is refinement after that. If you are unsure what compound to use, start with a medium and work outward from there. It is slower than starting with the fastest tire but it will save you a lot of time figuring out what went wrong when the fast tire fails to deliver.
