Want your Axial SCX24 or Traxxas TRX-4M to feel more planted without turning it into a pile of parts? Start with the weight and grip of the model, not a long list of fashionable upgrades. On a micro crawler, where each component is small, where you add mass can matter as much as how much you add.
The most effective first step is usually to lower the centre of gravity and improve the tyres’ contact with the ground. Then reassess before adding more. That measured approach can improve stability while keeping the steering and suspension working freely.
Key Takeaways
- Prioritise low, well-placed brass rather than adding weight everywhere.
- Front steering parts and wheel weights can help keep the front tyres loaded, but too much mass can make the model sluggish and increase mechanical strain.
- Choose tyres, wheels and inserts for your exact model and intended surface; check fitment before ordering.
- Install upgrades with the right small tools, gentle torque and suitable threadlock where appropriate.
- Change one thing at a time, then check how the whole model responds.
1. Brass weights: place mass where it helps
Could a small amount of weight make a micro crawler feel more composed? Yes, if it sits low and in a useful position.
The centre of gravity (CG) is the point around which the model’s mass is balanced. Lowering it reduces the leverage that can tip the vehicle when it is angled. Adding weight near the front can also help the front tyres stay in contact on climbs. But balance matters: excessive front bias may reduce the rear tyres’ contribution, while excess total weight can slow the model and load its drivetrain.
Brass is useful because it is denser than many common lightweight materials. That means a compact brass component can add meaningful mass without taking up as much space. It is the location, not simply the material, that makes the difference.
It is also worth distinguishing unsprung mass from chassis weight. Unsprung mass is weight carried by the wheels and axles rather than by the sprung chassis. Wheel weights and brass steering knuckles add mass low down, but they also make the moving parts work harder. A low-mounted chassis skid plate adds weight in a different way: it lowers the chassis mass without being a wheel-mounted weight. Either can help, but neither is a reason to add brass indiscriminately.
For SCX24 owners, RC Overhaul’s brass inner wheel weights are listed as 60g in total and designed for RC Overhaul’s compatible 1.0-inch beadlock wheels. Check the wheel fit carefully before buying; do not assume they fit every SCX24 wheel.
For a lower, central chassis option, the Fastrax SCX24 brass centre chassis skid plate is listed at 13.8g. It is a more measured addition than loading every wheel with ballast.
On the TRX-4M, options include Traxxas brass wheel weights, brass axle covers and brass 7mm hex wheel hubs with axle pins. Each places weight differently. Check the wheel and model compatibility for your particular setup before choosing.
Pro tip: Add one weight-related upgrade at a time. If steering response becomes noticeably heavier, or the suspension no longer feels free, treat that as a cue to reassess, not to add more brass.
2. Tyres and wheels: make the contact patch count
Is your crawler struggling because it needs more weight, or because its tyres are not suited to the surface? Tyres are worth checking before you commit to extra ballast. The compound, tread and foam insert all affect how the tyre meets the ground.
A softer tyre can deform around uneven surfaces, while an insert supports the tyre from inside. The right combination depends on your model, wheel and where you run it. A tyre that is too tall or wide can also rub against the body or suspension, so bigger is not automatically better.
When comparing wheels, you may see beadlock in the description. A beadlock wheel clamps the tyre’s bead to the rim with a retaining ring rather than relying on glue. It can make tyre changes more straightforward, but wheel diameter, width, offset and hub fit still need to match your vehicle.
Browse AT Models’ RC car wheels and tyres, and check the exact model specification before ordering. The SCX24 and TRX-4M are different platforms; a part that looks close may still have the wrong fit.
Pro tip: Check tyre clearance with the body fitted and the steering turned fully in both directions. Look for contact with the body, links and suspension before taking the model out.
3. Steering parts and links: add weight with a purpose
Where is extra front weight most useful? Often at the steering end, where it can help keep the front tyres loaded while still replacing a functional component.
On the SCX24, Axial brass knuckles are a model-specific left-and-right pair listed for SCX24 and AX24 models. Knuckles support the front wheel hubs and pivot as the wheels steer, so this upgrade adds mass at the front corners. Axial also lists a brass rear upper link mount for the SCX24; consider it as part of a balanced build, not an automatic first choice.
For the TRX-4M, Traxxas brass steering blocks are listed at 7g each. They carry the front wheel hub and pivot to steer, putting weight near the front wheels.
Pro tip: Fit steering parts carefully and check that both sides move freely afterwards. If you are unsure whether an upgrade matches your version, use the Parts Finder or ask the AT Models team to help confirm fitment.
4. Scale extras: add lights, not just ballast
Want an upgrade that changes the look as well as the function? A lighting kit can add a convincing scale detail without being another weight-distribution modification.
The Traxxas TRX-4M Pro Scale LED Light Set for the Defender includes front and rear lighting with a light harness. It is a model-specific accessory, so check that your body is compatible before ordering.
For a closer look at the platforms, see the Axial SCX24 range or the Traxxas TRX-4M Land Rover Defender. You can also browse TRX-4M spare parts.
5. Small tools, careful fitting
Are micro parts forgiving of rushed installation? Not usually. Small screws and threads are easy to damage if a driver slips or you overtighten.
A well-fitting hex driver helps the tool seat properly in the screw head. Keep a small parts tray nearby, work over a clear surface, and tighten screws only until secure. Use threadlock, a liquid that helps stop threaded fasteners loosening, to secure suitable metal-to-metal fasteners when the part instructions call for it. Avoid applying it to plastic threads.
Browse the RC tools and supplies range for workshop essentials. After fitting parts, rotate the wheels by hand and check steering movement, suspension travel and fastener security before running the crawler.
If you are considering changes beyond weight and grip, speak to the team before choosing components. Compatibility and the effect of added load matter on a small platform, and we’re here to help you make sense of the options, not just pick parts.
Key Takeaways
- Start with suitable tyres, then consider low, front-biased brass if the model needs a lower centre of gravity or more front-end loading.
- SCX24 wheel weights have a specific wheel fit; check compatibility rather than assuming they suit every wheel.
- TRX-4M steering blocks, axle covers, wheel weights and hubs each place mass differently, choose for your intended build.
- Fit one change at a time, use the right small tools, and check movement and fasteners afterwards.
- For help selecting compatible parts, explore the Parts Finder or contact the AT Models team.
