WOW, Traxxas really crushed it with this bad boy. The Unlimited Desert Racer (UDR for short) is all-new, and by far Traxxas’ most scale vehicle ever–and it’s not like the TRX-4 is a slouch in that department. So yeah, details galore on this thing, and not just in terms of add-ons like the jack, reservoirs, quarts of motor oil, radator, etc. The UDR is also detailed in that its built just like a full-size desert racer, as the body-off pics will attest. We’re talking eight shocks, solid rear axle, swaybars, two functional spare tires, interior with driver and navigator figures, removable chassis panels…the works.
As for tech, the UDR is a 4X4 of course, with 6S-rated Velineon power via a VXL-6S speed control and 2200Kv motor. Traxxas supplies their TQi transmitter, which is ready to accept the Traxxas Link Bluetooth module for complete radio adjustability and telemetry functionality via the free Traxxxas Link app. Top speed per the box is 50+mph (see speed chart below), and the Unlimited Desert Racer will hit stores at $750-$800 depending on your dealer.
Here’s the real truck Traxxas based the…oh wait, no, that’s the RC truck in action! It’s a replica of Justin Lofton’s FOX race truck. Traxxas also offers the URD in red and black RIGID colors–see the gallery below.
Traxxas refers to the UDR as a “Pro Scale” truck. Its wheelbase is 16.5 inches, which works out to right in between 1/7 and 1/8 scale compared to the 125-inch wheelbase of a full-size desert racer. Overall length is 27.3 inches, and the truck is 13.6 inches wide.
Here’s how the UDR scales out compared to a Slash. This is actually two separate shots put together in Photoshop, and the Slash looks a little weird because it was shot with a wider lens–but you get the idea.
With the spare tires removed, you can see the fuel cell complete with filler necks, racks of quart oil containers, and scale batteries next to them. The spare driveshaft is “real,” you can actually install it as a spare part. You can also see the fire extinguishers and (non-functional) shock reservoirs, and the radiators even have free-spinning fans inside. And look in the bumper; there’s a jack and handle tucked in there.
The tires are replicas of BFGoodrich KR3s and measure 5.3 x 2.2 in. (134 x 57mm). They’re glued to one-piece wheels.
The body comes off as a single piece once you remove 12 screws, but there’s no need to take the body off to run the UDR since battery access is below the truck. But removing the body does get you this amazing view!
All the panels between the cage tubes are removable, and the rear end is fully detailed complete with a pair of functional spare tires. Even the swaybar is constructed like the full size truck’s.
Here’s the truck with all the panels off and the interior removed. The “steel grey” coloring of the cage plastics is a nice touch.
These are the nicest-looking Lexan figures we’ve seen yet. The helmets are separate parts, and Traxxas got the decals right for all the switches and controls.
Each corner gets a pair of GTR shocks: one sprung, the other offering additional damping. Each of the front arms is two pieces to simulate the boxed construction of the full-size parts. Note also the realistic swaybar and brake detailing. The drive hexes are 17mm, and incorporate Traxxas’ signature splined design. 8mm axle nuts secure the wheels.
Plenty of travel here, just like the real deal.
Here’s a closer look at the shocks, with standard-length GTRs for size comparison. The UDR’s shocks get clamp-on spring perches to prevent pop-offs.
The rear end gets a solid axle with realistic trailing arms and brake detailing, functional travel-limiting straps, and steel upper links. The axle is sculpted like the full-size version, but there’s something going on where the driveshaft connects…
…and that would be the planetary gear reduction built into the axle, which is T-rick. By incorporating the reduction at the axle instead of letting the transmission do all the work, torque-twist is dramatically reduced–you can punch it from a stop with full 6S steam, and the UDR will just squat down, dig in, and tear off in a straight line. Massive 24x15mm bearings hold the steel spool, and look at the size of those gear teeth–the UDR’s drivetrain is stout.
Now lets take a look underneath. That big hunk of black plastic isn’t actually the chassis, at least not structurally. It’s just a cover/skid plate, and incorporates a slide-out locking cover for the batteries.
Remove eight screws, and we can see everything. The battery compartment can hold dual batteries or a single large pack. Instead of dangling leads with male plugs for the batteries, the make plugs are integrated into sockets in the chassis. If you want to run a single battery, a jumper-plug is included. The X-Maxx-style hold down keeps the pack(s) in place securely; the door incorporated into the skid plate in the previous photo is a cover.
This Traxxas render shows the transmission detail, revealing that it’s actually direct drive–the pinion meshes directly with the center differential’s steel ring gear. Gear mesh is fixed via pins, like the X-Maxx.
Driving the Unlimited Desert Racer
The pristine truck you see here is still waiting for its first run after I do a Facebook Live video with it. But I did log some wheel time with one of the UDR engineering team’s test runners at Traxxas HQ in McKinney TX, and I can tell you truck is really something else. I ran it on 6S, and as described previously, you really can just hammer the throttle and the truck will blast off dead straight with all four tires roosting. Unlike other high-power solid-axle rigs that twist up violently, the UDR reacts like the “real thing.” I ran the truck on a vacant lot with a mix of short, winter-brown grass, churned up Caterpillar tracks, and the lumpy footprints of the Traxxas full-size monster trucks that were there a few days earlier. The UDR blitzed through that stuff with its suspension pumping, and looked exactly like a full-size truck in action. It’s amazing the drilling this thing can take as the chassis just glides along. And while it seems like the UDR should tip easily given its scale width (which seems narrow compared to RC short-course proportions), the sway bars do their thing and the UDR will drift all day long. When full-scale racers in hang-the-tail-out disciplines like sprint cars, short-course trucks, and desert racing talk about “steering with the throttle,” they’re describing exactly what it’s like to drive the UDR off-road. Slinging the truck through turns sideways is balancing act between throttle input and steering angle, and a ton of fun. And easy; the UDR is equipped with Traxxas Stability Management, which you can dial up or down on the fly to control how much electronic “assistance” is delivered to match conditions and your skills (and yes, tough guy, you can turn it off). As soon as all the photos and video are in the can with RC Car Action’s test truck, I’ll give it a good thrashing and report back. Stay tuned.
Length: 27.32 inches (694mm)
Front Track: 13.57 inches (345mm)
Rear Track: 13.57 inches (345mm)
Ground Clearance: 2.27 inches (58mm)
Weight: 13.4lb (6.1kg)
Height: 10.29 inches (261mm)
Wheelbase: 16.53 inches (420mm)
Front Shock Length: 5.19 inches (132mm)
Front Threaded Shock Length: 5.19 inches (132mm)
Rear Shock Length: 6.3 inches (160mm)
Rear Threaded Shock Length: 5.55 inches (141mm)
Tires (pre-glued): 134mm x 57mm BFGoodrich® KR3 replicas
Wheels: Dual-diameter 40mm x 56/81mm
Speed Control: Velineon® VXL-6s