Boom Racing BRX01 1/10TH 4WD RC Scale Crawler

The Last Word in RC Scale?

The Boom Racing BRX01 may just be the most detailed, functional (and capable!) RC scale crawler money can buy. The BRX01 was, until the recent release of the BRX02, the flagship model of the Scale 4WD Series. That’s Boom Racing’s line of scale vehicles based on realistic appearance and performance of full-size models.

The BRX01 was designed with ideas and feedback from the RC hobbyist community, making it somewhat unique in this niche. But there’s more to this machine than may be initially apparent; Boom Racing and partners have created a host of mods and options for this vehicle that are all ‘bolt-on’. The end result is a model that you can plan on paper before even starting your purchase and what you can finish with may be your own take on the LC70 kit.

Excellent In Stock Form

Upgrades aside, the Boom Racing BRX01 in its stock form is a very complete kit. It includes all of these as standard:

• a 2-speed transmission with included waterproof mini servo;
• anti-torque twist transfer case (you can choose to use either the clockwise or counter-clockwise rear outdrive during assembly);
• a high-clearance skid plate with rear 4-link geometry (and bolt-on compatibility for front and rear leaf suspension if desired);
• steel drive shafts and helical-cut diff gears;
• strong steel axles and universals;
• BTA (Behind The Axle) steering assembly;
• 7mm links with 4mm threads and stainless steel ball-ends;
• quality oil-filled, aluminium shocks with two different multi-stage coil-over spring choices; and,
• reversible steel beadlock wheels for adjustable track width.

That’s quite a list of highlights! But on top of this, the list of upgrades available for this machine, all easily installed, is just downright impressive. And that’s just the chassis! The licenced Toyota LC70 ute (or pickup) body is hugely detailed as well and the KillerBody LC70 interior is gorgeous. The entire kit is so feature-packed that it’s difficult to know where to start when you’re trying to tell someone about it (or make a review video or write an article!).

Chassis Highlights

We’ll start with the chassis. The frame rails are billet-machined 7mm aluminium. The rails and all the brackets and mounts are finished in a smart black and there are copious holes that are pre-tapped (mostly M3) on all pieces. The holes are not just for the stock equipment but also form part of the bolt-on nature of the available upgrades for the BRX01. The thoughtful design is apparent throughout the model and it’s something I keep coming back to.

The frame rails feature integrated high-steer design with BTA steering linkage, helping to reach an impressive 45 degree approach angle. The motor and gearbox mount up-front, above and a little behind the front axle. There’s a short connecting shaft to the transfer case the vehicle’s mid-point, on the skid plate, and then there’s a quick-release body hinge system at the rear, sitting just above the waterproofed radio receiver box.

There is a 3-link with panhard rod setup for the front, allowing for the CMS (Chassis Mounted Servo) steering configuration. The rear is a standard 4-link configuration, allowing for adequate but not excessive articulation at both ends. The entire chassis is utterly rigid thanks to the precision machining of all parts. Once it’s all together (use of the included thread-lock is a must for this model!), the chassis is satisfyingly lightweight and completely firm. It adds to the sheer enjoyment of seeing this thing come together.

Suspension & Options

There are numerous mount points for the suspension, both front and rear. While the stock suspension is coil-over aluminium shocks at both ends, leaf suspension is available for front and/or rear. In real life, the LC70 is typically furnished with coil-over shocks over front live axle and leaf suspension over rear live axle. On our build, we’ve wanted to replicate that and so also ordered the leaf suspension kit and extended skid plate slider to make that happen. (Note, a list of all our upgrades and parts used can be found at the end of this article). Whether you use coils or leaves at either end, the resulting suspension system is plush, functional and nicely tuned to carry a styrene/hard body shell over trail and rock.

Geared Up Goodness

We mentioned front-mounted transmission and mid-mounted transfer case. In more detail, the transmission that mates to the motor up-front has a small linkage for 1^st and 2^nd gear modulation from a rear-mid mounted mini servo. This is included with the kit. If you set up the servo correctly on a compatible radio, you can select high and low and also stop in-between those for neutral. The motor can still spin in neutral, but the outdrive to the transfer case doesn’t spin in that alignment. This can add a little to your fun with scale driving adventures.

The stock pinion gear is a 12-tooth and the spur gear is a 28-tooth, both are 32P gears. The final drive ratio in first and second gears with a 12T pinion is 45.11 and 20.3 respectively. (This means first gear will see your transfer case delivering rotation 45 times slower than the motor’s speed and second gear is 20 times slower, so a motor spinning at 3000 rpm will deliver 66.5rpm in 1^st gear and 147.8rpm in 2^nd gear). This means a nice gap between first and second gear, so with a broad motor and pinion choice you really can enjoy super-slow crawling and a very useable walking speed, or faster on both counts if desired. Good!

Transfer Case Goodness

The transmission is good in stock form, but it gets better! You’ve already read the transfer case gives you a choice of clockwise or counter-clockwise rotation to the rear. If you choose the stock position of opposite rotation to the front outdrive, the ‘torque twist’ phenomenon is largely cancelled. That in itself is excellent.

However, Boom Racing has also made a few special options available as after-market purchases for your BRX01. Here’s the list:

• DIG (DIsengagable Gear): using a second servo, you can have three positions from the transfer case for your rear axle, while the front axle enjoys constant drive. The rear axle can be driven as normal, free-wheeled, or locked from rotating. It’s the locked position that’s interesting for two reasons:
  • first, DIG facilitates sharp cornering as the front wheels drag the vehicle in an arc around the locked inner rear wheel; and,
  • second, DIG allows you to load the front tires and suspension as you claw up a rock, then ‘pop’ the rear wheels back into motion as you accelerate up and hopefully over the obstacle.
• 2WD/4WD: a second mini servo is also needed for this one. It allows you to disengage drive to the front wheels (kind of like the DIG for rear, but without the locking option), so when you’re free-wheeling the front, you’re effectively in 2WD. Re-engage for 4WD.
• Overdrive: no servo needed for this one. There is a set of gears that grants 33% overdrive to the front axle, whilst the rear is driven at standard speed. This allows for sharper cornering and better manoeuvring on rock problems.

But Wait, There’s More!

Here’s where things get delightfully tricky: you can combine the 33% overdrive gears with either the DIG or the 2WD/4WD selection in the transfer case! As we wanted a more scale driving experience with our BRX01, we opted for the 2WD/4WD transfer case and mini servo upgrade. The axles in front and rear are always locked – there is no selectable diff-lock in the BRX range (yet), so this presents a small problem. With locked axles, the vehicle will unavoidably understeer, especially in the loose stuff. We wanted a scale experience, but also want some performance, so we made a compromise and went with both the 2WD/4WD transfer case AND installed the 33% overdrive gears.

The end result: the BRX01 drives and steers normally in 2WD, but for more traction and/or better steering on any surface, when you engage 4WD you also get that 33% overdrive in the front. This really helps overcome the locked diffs and yanks the vehicle in whatever direction you’re steering. Brilliant!

BRX01 Wheels and Tires

The wheels are 1.55”, 16-hole stamped ‘steelie’ beadlock units. The tires are Boom Racing SP Road Tracker in Gekko Compound and ship with open cell, single-stage foams. The wheels are amazing and the tires are adequate – good enough that we won’t replace our rubber until the stock units wear down. There are other options available that improve performance on the rocks, but for general trail and light crawling use, the tires are definitely Good Enough. The foams can be difficult to align, giving the tires a visible ‘wobble’ until you get everything seated exactly right. Not much can be done about this and it’s a minor thing – but noteworthy for the details-oriented hobbyist to be aware of.

The wheels are special, though – and not just because they’re pleasingly weighty and beadlock type. The wheels are reversible! In stock form, you get the 16-hole steelie rims facing outward for a 7.5” track width and very factory wheel look. However, if you reverse-mount the wheels you get a deep-dish, mag-wheel look and increased track width of half an inch on each side. It’s a truly clever way of adding configuration options in the OEM gear, looking great in either setup. We’ve opted for the stock width and they look fabulous.

Electronics & Mounting

As is typical of RC model kits, you must supply your own motor, radio system, steering servo and ESC (Electronic Speed Control). Plus, any additional electronics such as lighting kits, sound, and so on. This is standard for RC models and whilst the running gear is very strong and well made, there’s no need to go crazy with the power system as you won’t want to beat too hard on the pretty body. This vehicle is all about smoothness and scale enjoyment.

We went with a 5-pole motor for that buttery-smooth, low-speed torque. We matched the Holmes Hobbies 550 13-turn CrawlMaster Sport with a Carisma ARC-2 ESC. The BEC (Battery Eliminator Circuit) in the ARC-2 can output 6v or 7.4v – it’s a similar unit to the HobbyWing WP-1080, another favourite. We went with a 6v jx Servo WP5323LV for steering and the Power HD TR-4 mini servo for the transfer case. Our electronics were finished off with the KillerBody light kit and a small light bar on the high-mount bumper. More on that soon.

This isn’t the end for the electronics. There’s a special little extra with the installation on the BRX01! The radio box is a gorgeous plastic component with brass-inset nut-locks for the lid, a slick silicone gasket for the JST wires to pass through, and a VIN plate that clamps on the top with your vehicle’s VIN (Vehicle Identification Number) – and it’s a unique number for every BRX01 unit! Boom Racing have a program whereby every BRX model owner can register their VIN to be part of the BRX Owners Club. The VIN is your automatic and unique entry number for any Boom Racing-sponsored competitions (HK based, typically) and for the rest of the world, it’s a fun talking point amongst owners. Our number is 1236 and we drive with others who are lucky enough to have numbers in the low three-digit range. Special!

BRX01 Build Experience

What’s it like to build? In a word, enjoyable! The manual is well-compiled and easy to follow. The parts are presented beautifully, so you know you’re building a premium kit. There is supplied fluid and materials as needed, from black grease and thread lock to siliking grease and wire screw-retainers. The boxes are very attractive and all parts are packaged carefully.

There was only one error in the manual I found during the build process, and it was minor (6mm gap between motor and spacer rather than the 10mm noted in the manual – easily overcome with a spare fiber collar I had lying around). The chassis goes together swiftly, partially because the axles and transmission are already assembled and partially because there just isn’t a lot to do. You’ll get the chassis done in an afternoon.

The body takes more care and attention, as both paint and assembly take some planning and care to be sure you get a good result. On the whole, it’s an enjoyable build and with the deep potential for tuning and modifying the vehicle to your particular taste and needs, one you’ll be sure to find quite rewarding.

BRX01 Specs and Details

Some extra details that are best listed as bullet-points rather than in article form (or you’ll be stuck here reading all day long!). There’s a lot to get through so we’ll break this into parts. Here’s more detail on the chassis, axles, suspension, drivetrain, transmission, steering, body and overall specifications:

Chassis

The BRX01 chassis has a few design considerations that you won’t find on most other models. From front to rear:

• The CMS setup has multiple adjustment positions for servo mounting, giving you flexibility with different servo options – useful if you have a highly raised suspension setup, for example;
• Relating to the servo adjustment options, the shock mount points on the chassis offer a wide range of positions, particularly in the front. The shock mounts are modular and reversible for different front/rear bias and can even be inverted for those (rare) installations that want to really give the chassis some lift!
• Silicone-sealed, waterproof receiver box keeps your receiver dry;
• Also adjustable up-front, the motor position can be vertically adjusted for lower center of gravity or higher clearance, again giving you flexibility with your vision for setting the car up to your liking;
• The billet machined aluminium frame rails have accurately drilled and M3-tapped mount holes right along their length, not only allowing for possible Boom Racing mods but also accommodating whatever setup you may be adding on your own – this also saves weight, so it’s a double-plus feature!
• Lastly, the rear-mounting body hinge system has sufficient clearance that if you add a tow bar to the rear underside of the tray, as we did, it still fits unhindered behind the hinge system without a problem.

Axles

The axles also have some useful design considerations built-in:

• BRX70 PHAT™ high pinion heavy duty cast metal axle for increased weight down low;
• BADASS™ heavy-duty steel universal shafts with over 45 degree steering angle;
• AR44 heavy-duty, keyed steel-cut bevel gears for high performance and durability;
• Adjustable caster angle for tuning;
• Knuckles have multiple mounting positions, also helpful for tuning;
• Reversible axle bevel gear positions, giving flexibility for either shaft direction from the flexible design of the transfer case outdrives;
• Leaf spring over and under axle setup enabled, including detachable aluminium CNC truss – helpful for leaf installations that don’t need it attached.

Suspension

• The shocks are full aluminium, two-stage, spring-loaded and oil-filled;
• Shock bodies are threaded with adjustment collars for pre-load and body height adjustment;
• Standard springs are medium firmness and the kit includes a set of softer springs also;
• Leaf springs can be easily installed with additional hardware – no permanent modification needed to the chassis;
• In stock form, front setup is 3-link with panhard and rear is triangulated 4-link.
• Front shock mount config gives 52 possible mount positions (but 26 is more likely what you’ll be using – the other 26 require the mounts to be inverted for some serious lift!);
• Rear shock mount positions give 12 possible mount positions;
• All links are 7mm aluminium hard adonized rods with M4 thread;
• Rod ends are all BADASS ™ Heavy Duty with Rust-Resistant S/Steel pivot balls.

Drivetrain

• In stock form, the BRX01 is full-time 4WD, shaft-driven from separate transfer case;
• For motor installation, there’s a clever pinion-spur gear mesh guide to ensure your gear mesh is just right;
• All gears in the model are heavy-duty, steel cut gears – no cast parts to worry about (I still have nightmares from the GF02F experience!);
• Drive shafts are heavy-duty steel units with universal joints (‘Voodoo’ branded);
• Transfer case has what Boom Racing calls ‘SRD’ (Selective Rotational Drive) – two outdrives to the rear in opposite directions give you more options.

Transmission

• The transmission has a small footprint with integrated 2-speed high/low selection;
• There are adjustable motor mount positions for either a low CoG (Center of Gravity) or high-clearance installations, as needed;
• Spur and pinion are 32 pitch; included pinion is 12T with a possible range from 9 to 16-tooth;
• Spur gear is reinforced plastic, 28-tooth.

Steering

• BTA steering helps with clean approaches and looks more realistic;
• Tie rod, panhard link and drag link are all stainless steel (plastic rod ends, s/steel ball ends);
• Drag link and panhard are counter-threaded for easy length adjustment (ie. turn the shaft rather than disassemble and change individually).

Toyota LC70 Body

• Officially licensed Killerbody Toyota Land Cruiser 70 Hard Body kit, ABS hard plastic construction;
• Features highly-detailed scale parts (door mirrors, interior mirror, air intake, snorkel, dashboard, steering wheel, window wipers, front wheel arches, chrome radiator grill, antenna, full filler cap, door handles and badges);
• Ready for LEDs (not included) – we used the Killerbody kit but had to solder custom 3mm LEDs to fit included light buckets;
• Optional extras available including full interior, moving windows and other scale details (not included);
• Quick release LC70 body hinge and mounts for easy access to chassis components – additional tool-free kit available and used in our build.

BRX01 Specifications

• Length: 462mm (chassis) / 523mm (with body);
• Front Track Width: 188mm;
• Rear Track Width: 184mm;
• Ground Clearance: 26mm;
• Weight: 1880g (chassis) / 2560g (with body);
• Height: 132mm;
• Wheelbase: 313mm;
• Approach Angle: 45 degree (with body);
• Departure Angle: 35 degree (with body);
• Breakover Angle: 35 degree (with body);
• Front Shock Length: 80mm;
• Rear Shock Length: 80mm;
• Wheels: 1.55″ Internal Beadlock;
• Tires: 3.46″ x 0.94″ (88mm x 24mm);
• Hex Size: 12mm;
• Motor Size: 540/550 (not included);
• Transmission: 2-speed Hi-Lo, Remote Shifting;
• Transfer Case: Anti-Torque Twist w/ Selective Rotational Drive (SRD);
• Gear Pitch: 32P Pinion/Spur, 48P T-Case;
• Chassis Structure/Material: 7mm Billet Machined Aluminium;
• Drive System: Full Time Shaft Driven 4WD;
• Steering: Chassis Mounted Servo.

Included in the BRX01 Kit

• BRX01 1/10 4WD Chassis Bolt-On Kit BR8001;
• JX Waterproof Mini Servo with Metal Gears;
• Quick Release Body Mount and Hinge for LC70 Body;
• 32 Pitch 12T Steel Pinion Gear;
• 25T Low Profile Aluminium Servo Horn;
• Maintenance Kit (Shock Oil, Black Grease, Siliking Grease, Thread Lock);
• Cable Wiring Retainer Set (18pcs);
• Killerbody Licensed LC70 Hard Body Kit KB/48601;
• BRX01 Owners Card (Numbered) with Chassis VIN#;
• Basic Tool Kit.

Required to Complete Kit

• 3-Channel Radio System (greater if using additional servos or light control – we used the 6-ch FlySky GT5 and it’s perfect!);
• ESC (electronic speed control);
• Steering Servo;
• 540 or 550 Motor (27T for off-road / 35T for crawling matched with provided 12T pinion gear);
• Battery & Charger (NiMH or LiPO is fine; we use 2S for long-running and 3S for shorter jaunts);
• Tools.

Our Impression

This is a well-rounded kit that has clearly been lovingly designed and assembled by hobbyist-minded people. We thoroughly enjoyed the build and driving it is FUN! (I’ve just come back to the computer to finish writing this after running another battery through it this evening after sunset). I’m loving the 2WD/4WD selection and highly recommend both that and the overdrive mods in combination. Brilliant!

Grab some lights for yours as well, as driving on trails after dark adds another dimension of enjoyment to the scale truck experience. Here’s our video review and below that is a list of accessories and upgrades we used, all from AsiaTees (we use affiliate links to help support RC-TNT – thank you in advance for using them, if you’re so inclined!).

Upgrades and Electronics We Used

• Boom Racing BRX01 1/10 4WD Radio Control Chassis Kit w/ Killerbody LC70 Hard Body Kit Set; Part: # BR8002
• Killerbody Cockpit Interior Set for Toyota Landcruiser LC70 Hard Body; Part: # KB/48601
• Boom Racing BRX01 Mini Servo Mount Set for BRX01 (without Mini Servo); Part: # BRLC70100
• Boom Racing BRX01 SWD (Selective RWD/4WD) Transfer Case Kit for BRX Chassis; Part: # BRLC70301-SWD
• Boom Racing BRX01 “Tool Free” Aluminum Quick Release Latch; Part: # BRLC7062
• Boom Racing BRX01 Rear Leaf Spring Conversion Kit; Part: # BRLC7064
• Boom Racing BRX01 Center Rear Skid Slider For Leaf Spring Setup; Part: # BRLC7072
• Boom Racing BRX01 KUDU™ High Clearance Bumper Kit for BRX01 w/ LC70; Part: # BRLC7094
• Boom Racing BRX01 Front Inner Fender by VM; Part: # VM/D-AA16
• Killerbody LC70 Realistic Movable Opening Hood Bonnet Upgrade Set; Part: # KB/48611
• CChand Rear Bed Cage + Diamond Plate for LC70 Body for Boom Racing BRX01; PART: #CC/D-A035

ELECTRONICS USED:

• Carisma ARC-2 ESC
• Holmes Hobbies brushed motors (we used 13-turn 5-pole 550 CrawlMaster Sport)
• Killerbody LED Light System
• Flysky GT5 radio I use on many of my rigs (IMO the best budget radio system for ground and water vehicles):
• Steering – jx Servo 23kg 6V servo
• Transfer Case – PowerHD TR-4 Waterproof Mini Servo Metal Gear 7.4V 2.6KG; Part: # PH/TR-4

More Info

Here’s the manufacturer’s site for the BRX01: https://www.boomracingrc.com/BRX01