Rock Crawling Adventures
A Father-Son RC Project
Introduction
Platform: Traxxas TRX-4M (97054-1) → Injora BUG18 Beetle
Welcome to our upgrade roadmap for turning a stock TRX-4M into a serious rock crawling rig. This guide documents a father-son project designed around learning together, building skills, and having fun along the way.
Why This Project
Alasdair and Atticus have always been fascinated by vehicles—not just playing with them, but understanding how they work. We wanted a low-cost way to take things apart and put them back together, learning mechanical skills along the way.
The TRX-4M is small enough to work on at a desk, but complex enough to teach real concepts: suspension geometry, gear ratios, center of gravity, electronics.
The Traxxas TRX-4M turned out to be the perfect platform:
- Strong aftermarket support with multiple manufacturers making high-quality upgrade parts
- Modular design that’s meant to be disassembled and modified
- Active community with plenty of guides, videos, and forums
- Reasonable scale for young kids to handle and help work on
The Journey
The upgrades are organized into seven epochs—each a distinct build session with its own theme, parts list, and milestone. The progression is intentional: we start with the foundation (chassis, suspension, bearings), add capability (electronics, wheels), then tune for performance (gears, weights, brushless).
Primary Use: Indoor/backyard crawling with rock park visits
Summary: The Complete Journey
| Epoch | Name | Focus | Cost | Cumulative |
|---|---|---|---|---|
| 1 | Big Build Day | BUG18 Body + Chassis | $130-160 | $130-160 |
| 2 | New Brain Day | Electronics | $58-83 | $188-243 |
| 3 | Big Wheels Day | Lift + Tires | $63-85 | $251-328 |
| 4 | Rescue Rig Day | Winch + Lights | $44-50 | $295-378 |
| 5 | Rock Ready | Performance | $40-45 | $335-423 |
| 6 | Heavy Metal | Brass Weights | $60-90 | $395-513 |
| 7 | Lightning Upgrade | Brushless | $80-120 | $475-633 |
Epochs 1-5 (Fully Capable): ~$335-423 All Epochs: ~$475-633
How to Use This Guide
Each epoch chapter includes:
- Overview of what you’re doing and why
- Bill of Materials with part numbers, links, and costs
- Q&A answering common questions for that epoch
- Resources with video guides and community discussions
The reference section at the end covers electronics deep-dives, parts sourcing, and compatibility notes.
Local Places
- Riders — Local hobby shop for parts
- Reaction RC Hobbies — Parts + crawling course ($10/day, rentals available)
- Grand River RC — Racing track (less relevant for crawling)
Community Resources
The TRX-4M has an active online community. These are good places to find build inspiration, troubleshooting help, and upgrade discussions.
- r/rccars — General RC community; good for broad questions
- r/crawling — Dedicated to rock crawling; more focused discussions
- r/SCX24 — Axial’s 1/24 scale competitor; similar scale, many overlapping techniques
Tip: Search “TRX-4M” within these subreddits for platform-specific posts.
YouTube Channels
These channels regularly cover TRX-4M builds and upgrades:
- RC Crawler Therapy — Detailed mod guides
- Half Chrome Diecast — Reviews and comparisons
- RC Crawlers — Scale builds and trail runs
Forums
- RCCrawler.com — Long-running forum with deep archives
- RCGroups Scale Section — Active community discussions
Last updated: January 2026