5 Epoch 5: Rock Ready
Epoch 5 Total: ~$40-45
Low-range gears for technical climbing, skid plates for impact protection. You’ve got the foundation sorted, the electronics ready, the wheels dialed—now you’re tuning for the rock crawling course where impacts are expected.
After this epoch: Technical climbing ability, impact protection, ready for the rock course.
The kids’ job: First rock park trip!
5.1 Bill of Materials
The 4M-55 transmission from Epoch 2 already includes 40.3:1 underdrive gears—59% slower than stock. Combined with the Roverin’s FOC control and 200% drag brake, you may already have sufficient crawl speed. Evaluate after testing before purchasing additional low-range gears.
5.2 Q&A
Do I still need low-range gears after Epoch 2?
Maybe not. The 4M-55 transmission already provides 40.3:1 underdrive (59% slower than stock). Combined with the Roverin’s FOC control and 200% drag brake, you likely have excellent crawl control already. Test first before buying additional gears.
What’s the difference between low-range gears and underdrive gears?
Both slow the truck down. Underdrive gears compensate for larger tires or provide crawl speed. Low-range gears go even slower for technical climbing. They can stack—but with the 40.3:1 gears already in the Epoch 2 transmission, additional reduction may be unnecessary.
Do I need all the skid plates?
The chassis skid plate (#9766) is the most important—it protects the battery and electronics. Axle skid plates (#9765) add armor to the axle housings. If budget is tight, start with the chassis plate.
5.3 Reference
5.3.1 Rock Course Durability Checklist
For courses designed for larger vehicles (where impacts are expected):
Video Guides:
- TRX-4M Gear Ratio Explained — Understanding crawl speed
- Skid Plate Install — Armor installation
Community Discussions: