Big Build Day

Complete chassis swap with new suspension, servo, and bearings. Alasdair wants a "beetle car" so we're going with the BUG18 body kit which includes the LCG aluminum chassis. You have to disassemble most of the truck anyway for the chassis swap — might as well do all the internal upgrades while it's apart.

After this epoch: New beetle body, lower center of gravity, better articulation, reliable waterproof steering, smoother drivetrain, brass weight at the lowest points.

What we bought, and why

BUG18 body

Alasdair specifically requested a "beetle car" — this body satisfies that request while including the LCG aluminum chassis, bumper, roll cage, rock sliders, and magnetic body mount in one kit.

7kg servo over 11kg

The INJS2065 is IP66 waterproof (can run in rain or underwater). The 11kg INJS11 has more torque but is NOT waterproof. Given Michigan weather, snow driving, and unpredictable toddler situations, waterproofing was prioritized. 7kg torque is plenty for a TRX-4M even with brass weight upgrades.

59mm brass/aluminum shocks

Brass ends add ~20g of unsprung weight at the lowest point possible, improving stability. Threaded preload adjustment allows tuning. These replace stock shocks that were causing body sag.

50wt/710CST shock oil

Heavier oil = slower rebound = more forgiving suspension. When a toddler drives off a step or tips sideways, the shocks compress and recover slowly and predictably instead of bouncing. This weight is on the heavier side (710CST is closer to 60-70wt equivalent) which is ideal for slow, deliberate crawler movement with a young driver.

Sealed bearing kit

Stock TRX-4M uses bushings, not bearings. Sealed bearings roll smoother, reduce friction, and keep out water/dirt — important for snow and wet conditions.

Carbon fiber double decker tray

Provides clean mounting for the brushless ESC, receiver, and battery. Two-tier design keeps wiring organized and components accessible. Lighter than aluminum alternatives.