Arrma Big Rock 3S BLX vs Redcat Volcano EPX ProWhich Should You Buy?

The Redcat Volcano EPX Pro at its price point is one of the cheapest brushless 4WD trucks you can buy. The Arrma Big Rock 3S BLX at its price point costs significantly more. That price gap buys a significantly better truck in every measurable dimension, and this comparison makes it clear why spending a bit more upfront usually saves you money and frustration in the long run.

Performance isn't close. The Big Rock hits 50 mph on 3S power while the Volcano manages 35 mph on its 2S system. That's a 15 mph gap driven by the Big Rock's higher-voltage battery platform and more capable brushless motor. The Big Rock's acceleration is sharper, its mid-range punch is stronger, and it just feels like a more powerful machine from the first pull of the trigger. The Volcano's 35 mph feels adequate until you drive the Big Rock, and then it feels slow. That's the nature of speed in this hobby. Once you've experienced faster, it's hard to go back.

Physically, the Big Rock is the larger truck at 20.47 inches long and 14.57 inches wide versus the Volcano's 16.93 inches long and 12.2 inches wide. The Big Rock's 12.91-inch wheelbase is over 2 inches longer than the Volcano's 10.63 inches, providing better high-speed stability and smoother handling over rough terrain. Weight favors the Volcano at 5.73 lbs versus 6.77 lbs for the Big Rock, but the lighter weight doesn't offset the smaller platform's instability at speed. Ground clearance is comparable at 2.05 inches for the Big Rock and 2.17 inches for the Volcano, so neither truck has a meaningful advantage clearing obstacles.

Build quality is where the gap really shows. Arrma's Big Rock uses metal gear differentials, a stiff anodized chassis, and oil-filled shocks designed to handle the forces of 50 mph bashing. The Volcano EPX Pro uses lighter-duty components appropriate for its speed range but noticeably cheaper in feel and durability. The plastics are thinner, the shocks have less damping precision, and the drivetrain uses smaller bearings. After a few hard crashes, the Volcano's plastic components start showing their budget origins with cracked arms and stripped gears. The Big Rock absorbs hits that would break parts on the Volcano without flinching.

Battery systems differ completely, and this matters for your long-term investment. The Big Rock runs 3S (11.1V) packs while the Volcano runs 2S (7.4V). If you start with the Volcano and later upgrade to a 3S truck, your batteries won't carry over. Starting with a 3S platform like the Big Rock means your battery investment grows with you as you add more trucks to your collection. The Volcano ships with a 3000mAh 2S pack, while the Big Rock specs 3200mAh 3S. Both are waterproof, which is actually a nice feature on the budget Volcano that not every entry-level truck offers.

The Volcano EPX Pro exists for buyers with a hard budget limit. It gets you brushless 4WD at the lowest possible price, and it's genuinely fun within its performance envelope. For a kid's first RC truck or someone testing the waters of the hobby, it's perfectly adequate. But for anyone who can stretch their budget, the Big Rock is a generational leap in every category: speed, durability, parts quality, and long-term value. The extra money buys you a truck you won't outgrow in three months and batteries that transfer to your next truck.