Losi Lasernut U4 1/10 4WD Brushless RTR Rock Racer (Black) w/2.4GHz Radio & Smart ESC

Losi Lasernut U4 1/10 4WD Brushless RTR Rock Racer (Black)
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The Losi Lasernut U4 1/10 4WD Brushless RTR Rock Racer is a scale replica of the renown Lasernut Unlimited U4 FIS (Full Independent Suspension) rock race buggy. Starting with the Losi TEN platform as a base, the Lasernut model adds items rock racers demand such as aluminum shocks, sway bars and adjustable turnbuckles. Working together with BFGoodrich Tires, the Lasernut U4 has scaled down KM3 tires that have an aggressive tread pattern that is capable of tackling a wide variety of terrain - from dirt and sand to chunky rocks and slick slabs.

The Lasernut is currently the only complete Unlimited U4 FIS racer on the market featuring all the technological advances drivers demand including the Spektrum Smart 130A Brushless ESC and Spektrum 4-Pole 1900kv 550 motor providing greater efficiency improving run times with increased power. Of course, the ESC is waterproof, completely programmable and comes pre-wired with a high-current IC5 connector. Drivers stay in control with a DX3 transmitter, a Spektrum AVC receiver with steering priority, and an officially-licensed Lasernut race-inspired scale U4RC body/roll cage with two different graphics and color variations. The Losi Lasernut Rock Racer is the ultimate U4 racer with scale looks, insane speeds and performance.




  • TEN 4WD Platform
  • Spektrum™ 130A Brushless SMART ESC and 4-Pole 1900kv 550 Motor
  • Spektrum DX3™ 2.4GHz radio system with AVC® and optional telemetry
  • Waterproof Components
  • 12mm race inspired threaded aluminum bodied shock absorbers and shock caps
  • Officially-licensed Lasernut Racing Scale Body & Cage
  • Officially-licensed BFGoodrich® Mud-Terrain T/A® KM3 Tires
  • Officially-licensed Raceline 2.2 Wheels
  • Sway bars
  • Three Oil Filled Gear Differentials
Approximate Assembly Time: No assembly required
Ball Bearings: Full set
Battery: Sold Separately
Body: Trimmed and painted
Brakes: Integral with ESC
Bushing Material: Metal
Charger: Sold Separately
Chassis: 0.12"
Completion Level: Ready-To-Run
Differential: Sealed viscous filled
Drivetrain: 4WD
Drive Type: Forward/Brake/Reverse
Final Drive Ratio: 12.97:1
Front Track: 13.25" (336mm)
Power Type: Electric
Gear Pitch: MOD1
Ground Clearance: 1.75" (44mm)
Internal Gear Ratio: 3.89:1
Max Battery Dimensions: 5.45 x 1.83 x 1.38" (138.5 x 46.5 x 35mm)
Motor Type: Brushless
Pinion: 12T
Product Height: 8" (203 mm)
Product Length: 24.3" (617 mm)
Product Weight: Varies with equipment
Product Width: 13.25" (337 mm)
Radio: Included
Rear Track: 13.25" (336mm)
Receiver: Included
Scale: 1/10
Servos: Included
Shock Type: Oil-filled aluminum body
Speed Control: Included
Spur Gear: 40T
Suspension: Independent
Technology: Smart
Track: 13.25" (336mm)
Vehicle Type: Rock Racer
Water-Resistant: Yes
Wheelbase: 14.75" (375mm)

  • (1) Lasernut U4 4WD Brushless RTR Vehicle
  • (1) Spektrum™ Firma 130A Brushless SMART ESC (installed)
  • (1) Spektrum™ 4-Pole 1900kv 550 Motor (installed)
  • (1) Spektrum™ SR6100AT Receiver with AVC
  • (1) Spektrum DX3™ 2.4GHz Radio Transitter
  • (1) Product Manual
Needed to Complete:
  • 3S or 4S Hardcase LiPo Battery with IC5/EC5 Connector
  • 3S/4S Compatible LiPo Charger
  • Protective LiPo Storage/Charging Case

This product was added to our catalog on March 8, 2021

Wednesday, Nov 25 2020 (5 months ago)
Losi Lasernut U4 1/10 4WD Brushless RTR Rock Racer (Black)
This is exactly what you'd expect from Losi, not Team Losi, but Losi. Everything is "RTR" quality. It's a good rig to my experience but I've upgraded mine substantially to get it to a competition level.

If you're looking at this, expect broken drive shafts and sloppy steering, and potentially stripped hubs. With that said, once upgraded and replaced, this rig is a beast. It's so much fun to drive.
Saturday, Nov 21 2020 (6 months ago)
Losi Lasernut U4 1/10 4WD Brushless RTR Rock Racer (Black)
I'd wait for the V2 in hindsight. It drives great, awesome on trail. I'm literally going on the same trails as my crawler and having a blast. After 15 packs or so I broke a front axle going off a 3 ft ramp and landed awkwardly. So don't jump it. The huge tires and open wheel put way more strain on the axles compared to the other tenacity models. I blew the rear diff from trail running. I replaced the diff with losi TEN SCTE parts. Download the manual for the part numbers. I kept the stock ring and pinion for the gearing. I bought everything for all 3 diffs. I'll replace as I service them. The servo is very weak but works. I replaced it with a stock TRX4 servo I had. That works fine. So $150-$200 later the truck is ready. BTW, Losi support was excellent. For general use at the same price get the Arrma Typhon. Unless you really want to go in the woods, the Typhon is better in every way, even looks cool. So don't buy it and be surprised when you have the same issues.
Update: after replacing the diffs the rig has been rock solid under heavy use.

Edit: the rear diff went again after the SCTE 3.0 swap. It did last a very long time under heavy use. I bit the bullet and installed a vitavon rear diff case for $100. In the long run this is the least expensive solution.
BTW: I still really love this rig so that says something about the performance.