Build a UTB18 for Competition

Build a UTB18 for Competition

Who This is For

I’m a big fan of the Axial Capra UTB18. It’s been seemingly built for durable fun in a small size, but did you know it also has all the right geometry and dimensions to perfectly fit with WRCCA Mini 1.9 class specs? This isn’t by accident!

If you’re someone wanting to run in WRCCA Mini 1.9 class and you’re looking for something a bit different and like the idea of using your Axial UTB18 as a base, you’ve come to the right page! Follow this outline and you’ll end up with a competition-proven Mini chassis capable of helping you win your event.

Affiliate Note

This article necessarily has links to all the products I’m using for my rig. I’ve used affiliate links wherever I can because it helps support my work without costing you anything more – that’s a no-brainer! These recommendations are nonetheless legit and they’re the gear I’m using. I want to help you build your rig, and we’re going to do it honestly and with transparency.

Also, I’ve worked with RCAWD to develop the portal gears for the UTB18. I’ve linked directly to their storefront for all the bits I’m running.

RC-TNT HT Feather V2.36 Rear-LHS

Background

After we got our first Bambu P1S printers, my friend Harry T. and I got to talking. We both had Axial UTB18 ‘Baby Capras’ and both participated in local RC crawling comps. We set ourselves a challenge to each design a chassis for the UTB18 to improve its high center of gravity and its overall crawling ability.

For my design, I also decided to make it something people could download and build themselves. So, one of the parameters I set myself was to retain the original suspension, links and drive shafts, in order to minimise the outlay and complexity of the build.

Testing

I printed several iterations over that day and sent them to Harry. He tested them and reported back with his opinions. I’d modify the design, then send it back to him for more testing. The next day, we had a good working prototype. To honour Harry’s help, I named my chassis after him: the HT Feather.

I’ve since shared the story of its build on my YouTube channel and then driven it to second place at the 2024 ECCF, which is something of a Nationals event for Australian rock crawling. The chassis moves well, is easy to build, quite durable (in PLA+) and works amazingly well. I watched it stably out-crawl far more expensive rigs during the event and it was very satisfying to drive.

Since then, folks have been messaging me with something like “How do I build one like yours? Give me all the details, not just the chassis!”. This article is an answer to them, and also to you, if you’re interested in building your own budget beastie. Let’s go!

HT Feather v7 Rear Left

UTB18 Videos

If you’d like more background on the development of this machine, check out my Mini class videos on RC-TNT:

  1. My original Mini 1.9 Comp Rig: https://youtu.be/NkMp5FG-LlQ
  2. UTB18 Review: https://youtu.be/EJZytzGkbBs
  3. Upgrading the motor & ESC: https://youtu.be/e-ILpmQpH7E
  4. Replacing my Mini 1.9 with UTB18: https://youtu.be/qTZ1Ie6_u7Q
  5. My bolt-on comp chassis, free to download! https://youtu.be/plJ2p2RE-F4
  6. Getting the tires right: https://youtu.be/OziL7NPY4SU
  7. RCAWD Wheels and final tweaks: https://youtu.be/tgjrdzU7ySQ
  8. National 2nd Place and exploring suspension: https://youtu.be/isiTjDfnzd4
UTB18 Top-Down

The Parts

MODEL & CHASSIS

First, you’ll need an Axial Capra UTB18, of course! https://amzn.to/3X5S0lg

CHASSIS: Also, you’ll want to get my HT Feather chassis downloaded and printed. Full instructions are contained in the file and also on the download page. https://rc-tnt.com/project/rc-tnt-ht-feather-chassis-for-utb18-v2-36/

HARDWARE: a pack like this is handy: https://amzn.to/45acRWv. Use the button head screws in the prescribed lengths (8x of each 8mm and 12mm, plus the extra 4x 12mm for the newer rear piece).

RC-TNT HT Feather V2.36 Sliced

ELECTRONICS

RADIO: This guide assumed you’ll use your own radio system of choice. I’m running a FlySky GT5 (http://asiate.es/aff?l=150074&i=76070) with a budget and light-weight FS-A3 receiver: https://amzn.to/3R9Lbeu

SERVO: I ran this servo for 3 comp seasons and it was perfect: jx Servo CLS5830HV V2: http://asiate.es/aff?l=165766&i=76070

I’ve recently upgraded to the jx BLS-HV7132MG brushless model for some more speed: http://asiate.es/aff?l=155209&i=76070

MOTOR: With motors, you have a few choices. I really like this cheap and cheerful Surpass Hobby 1300kv Outrunner: https://amzn.to/3V87in2

ESC: And I’ve found the perfect pairing for this motor and either of the above servos is the Rhino 80A Brushless AM32 ESC: https://amzn.to/4bBxsp8 (we’re picking the 80A instead of the $14 cheaper 40A because of the 10A vs 3A BEC they come with. The 80A version is the obvious choice).

The previous ESC I was running was the Castle Mamba Micro X ESC, which worked fine too, but it made the outrunner motor quite loud with its lower PWM rate: http://asiate.es/aff?l=208954&i=76070

UTB18 Servo

GEARING

There are between 3 and 5 sets of gears to upgrade, depending on what outcome you want. I’ll give you the list and put an * next to the ones I’m running in mine.

*Transmission – Steel Gears: https://rcawd.com/en-au/products/rcawd-axial-utb18-steel-48p-transmission-gear-set-upgrade-parts-for-1-18-capra-trail?ref=mcc

*Portal Gears – Front Overdrive (24/17 – 22.78% O/D): https://rcawd.com/en-au/products/rcawd-utb18-48p-portal-gear-set-24t-17t?ref=mcc&variant=43370775838911

*Portal Gears – Rear Underdrive (27/14 – 10% U/D): https://rcawd.com/en-au/products/rcawd-utb18-48p-portal-gear-set-24t-17t?ref=mcc&variant=43370775806143

Diff Gears – Front Overdrive (31/13 – 6.45% O/D): https://rcawd.com/en-au/products/rcawd-axial-18-1-utb18-upgrades-35t-13t-40crmo4-differential-gears-axi212000?variant=42306402582719

*Diff Gears – Rear Underdrive (35/13 – 5.81% U/D): https://rcawd.com/en-au/products/rcawd-axial-18-1-utb18-upgrades-35t-13t-40crmo4-differential-gears-axi212000?ref=mcc&variant=42306452029631

UTB18 Portal Gears

SHOCKS, LINKS & SHAFTS

SHOCKS: I’m running stock shocks for now, but very soon will swap over to a set from Pricey’s Custom Crawlers. Check out this video to learn more.

LINKS: I’m still running the stock links that come with the UTB18, though I’ve been considering experimenting with shorter front links and longer, bent rear links. I’d have to make these myself, as I’m not aware of any on the market (other than made-to-order by the likes of Pricey’s Custom Crawlers and similar): https://www.facebook.com/profile.php?id=100057753455776

STEERING: However, you will want better steering and drag links than the noodley stock ones: https://rcawd.com/en-au/products/rcawd-axial-utb18-capra-upgrades-aluminum-alloy-steering-link-set-linkage-tie-rod-axi214001?ref=mcc&variant=42175530074303

DRIVE SHAFTS: I also ran the plastic drive shafts for an entire competition season without a problem. I changed to steel unis before the ECCF though, just to be extra careful – breakages suck! https://amzn.to/4bEIqdH

SERVO MOUNT: Another issue I noticed was the servo was wiggling on its plastic mount a bit, so I’ve recently upgraded that to alu: https://rcawd.com/products/rcawd-axial-utb18-capra-upgrades-aluminum-front-servo-linkage-mount-plate-rear-linkage-mount-plate-axi212009?ref=mcc&variant=42175477711039

LINK RISER: Lastly, I am soon going to experiment with this rear link riser, FYI: https://amzn.to/4c0X4LV

UTB18 Stock Links
UTB18 Shafts

WHEELS & TIRES

TIRE OPTIONS: This is an interesting one. There are a few options for tires. I’ve been running RC4WD’s 1.9 4.19” comp pins and have been very happy with them, including with the stock foams.

RC4WD’s site: https://store.rc4wd.com/rc4wd-bully-competition-19-scale-tires.html

RC4WD pin tires: https://amzn.to/3LyvFpK

I haven’t yet tested the new INJORA 1.9 4.19” Comp Pins, though I have them here ready to test soon: https://s.click.aliexpress.com/e/_DdpuUHh

The other tire to mention that was popular at ECCF was the HPI Rover in 1.9”. They’re sub-4” tires, but you can’t argue with Jakey Scholefield’s first place result with them on his PBCCP Vibe chassis (nor Zac Davidson’s third place on the same gear): https://amzn.to/3yJ7dyA

WHEELS: the best wheels to use for this setup are an easy sell. See the video in the list above for how I set them up, and buy them here: https://rcawd.com/en-au/products/rcawd-cyberwheelz-adjustable-weight-1-9-beadlock-wheel-rims-for-1-10-rc-crawler?ref=mcc

RC4WD Pin Tires
RCAWD Cyberwheelz

EXTRA MASS

This element of setup is somewhat a personal thing. However, if you’re building the rig to be like mine, and critically, with the RC4WD pin tires, I’ve found this setup to work best:

AXLES: stock plastic units with stock shafts

PORTAL OUTERS: https://amzn.to/3R87GAG (both ends)

FRONT PORTAL HANGERS: https://amzn.to/3X00dYf

FRONT PORTAL INNERS (KNUCKLES): https://amzn.to/3X3pRLy

You do end up with a front-heavy rig here. But remember, with the stock geometry (tilted skid aside) that the HT Feather chassis lets you run, in my opinion, the rig does better like this. I found it very predictable and it ascended things well, even with that rear weight. Indeed, the rear weight really helped it on steep descents, allowing the rig to be predictable in all conditions.

UTB18 Front Weights

BATTERY

The stock UTB18 battery won’t fit in the HT Feather battery tray. But it’s too big anyway, IMO. I recommend these, one for each comp course run: https://amzn.to/4bGJ5em

If you buy something else, be aware that not all 450mah 3S batteries fit. I’ve used these ‘E-Flite Blade 180’ batteries for years and have a bunch of them. They’re quality cells, have a really high charge rate (I’ve done 5C in a pinch at comps, though usually charge them at 2C) and they’ll give you 7 to 11 minutes of hard crawling in a 1/10 rig. Even longer in a brushless HT Feather!

UTB18 Batteries

Finishing Up

Now you’ve got everything you need to build a budget champion! Of course, budget is relative and combined, this all adds up to quite a bit. So, if you’re wondering in which priority to do thee mods over time, I’d suggest starting with the (free) HT Feather, the wheels and tires, and maybe even just front portal overdrive gears to begin with. See what you think and go from there.

Happy tinkering and enjoy your time on the rocks with your epic new comp killer!

HT Feather on rock
Craig Veness

Craig Veness

RC-TNT

Craig has been into radio control since the 90s and into RC crawling since about 2010, when a Losi MRC started the obsession! Now it's all rocks this and crawl that and upgrade all the things! ...You know how it is, right? Welcome home 🙂

RGT Intruder: An Important Release!

RGT Intruder: An Important Release!

Heard of RGT?

Before we get to the RGT Intruder EX86020 (available here), I think some context would be helpful. Previously a lesser-known manufacturer, Chinese company RGT have been making quite a splash with their 1/10 trail rig releases over 2022 and 2023.

For instance, you may have already seen our recent comparison article, “Which RGT is best for you?”. In this one, I compared three of their best and biggest recent releases: Rescuer, Challenger and Pro Runner. I’ve also looked at the Tracer, Pioneer, and the 136100 range either here or on the channel – and all have their merits.

3 RGT Models - Rear

What’s the Big Deal?

So, what’s the fuss about the RGT Intruder? Isn’t it just another car? Well, no: for a start, it’s their first big release for 2024. Secondly, it looks the same as the RGT Rescuer EX86190, which will inevitably lead to comparisons with the older, larger model. We’ll see below that this apparent similarity is only cosmetic in nature – but more on that in a moment.

I see it as an important next step after their successful, more ‘standard’ models. Their previous SWB (Short Wheel Base) models have been underwhelming, or, if finished beautifully as with the 136100v3, weaker than it should have been. (Both my 136100v2 and v3 have a broken front axle and both were the CVD joints not standing up to crawling). But now, folks are starting to pay attention.

RGT Rescuer EX86190 on Grass

The Big Reason

RGT has proven they can make great vehicles. They’ve shown how their own designs are working – obvious IP infringement aside with the bodies and often the tire treads. And they’ve shown that they can make a decently durable model that performs well AND has parts and upgrade availability. That’s actually quite a big deal.

As these models draw new potential customers to consider the brand, their newest model releases matter all the more. From where I’m watching, the RGT Intruder EX86020 is possibly their most important release. This is their first high-level scale model RC crawler that doesn’t have the extra bells and whistles that many folks disparage. It has a gorgeous body. The price suggests quality. The running gear is solid (U-joints in those front axles, for example). And it’s all 1/10 scale kit.

In short, this model needs to be good. Better than good. Newcomers to RGT are watching this one!

RGT Intruder Chassis Top-Down

What’s It Like?

The first thing that jumped out to me was that gorgeous body. I made a post on my YT community page that said something like, “Gosh, this car just looks amazing from any angle” – and it really does!

There are a bunch of extras they throw in so you can add more lights, mount a larger battery tray, add some scale extras and have a play with suspension mount points and so on. There’s a lot of good here, though the main ‘feature’ of this model is its appearance. I mean, just look at it!

RGT Intruder External Sides
RGT Intruder Included Parts

Body Issues

There’s only one issue with the body: it is not licensed. This has been the case for all of their crawlers, to my knowledge. Toyota may not be pleased, and I don’t condone the practice. Unlicenced bodies are a problem for the hobby, as are cloned parts. I really need to do a blog post on just this topic, as there are a few things to unpack here. But the car is pretty and the colour choices are all quite good.

This model comes with some extra plastics for both the cabin and the exterior of the body, like a rear-view mirror, extra spotlight cases, wipers, and so on. You need to fit these yourself. The folding side-mirrors come installed though, as do the door handles and the rear pillar air vents. If you do nothing with the extras after you unbox it, the car is still very complete. I also appreciate the captured body pins – you won’t lose these during a battery change on the trail!

RGT Intruder Captured Body Clips

RGT Intruder Interior

Well, it has one. My original RGT Rescuer did not have one (see? Even I’m comparing this car to the Rescuer! It’s inevitable!), though now the EX86190 does ship with an interior. I bought mine separately. The interior in the Intruder here is the same as the one I bought. This is a good thing, as it helps keep RGT’s costs down. It’s attractive, functional, and being polycarbonate, about as light as it could be. Good!

There are no lights in the cabin, but there are lights on all corners, controlled by a central module that’s attached to the underside of the body’s mold piece. It connects to the LED port on the all-in-one Receiver/ESC/Light Controller on the chassis. I’ll get to that further down.

RGT Intruder Front View
RGT Intruder Body Underside

Wheels and Tires

There’s the promise of performance, with vented tires (including foams), and they’re about as large as could reasonably fit under this scale of body. They’d be 43” tires in real life – and on this kind of vehicle, even something like 35” tires are BIG. So, RGT have pushed the performance there as far as they dare. It’s a compromise, scale vs capability, and I think it was the right move to max the diameter out.

They’re glued 4.31″ tires on plastic 1.9″ wheels. However, I do think the tire carcass is too stiff for the weight of this car. The foams feel about right, but the rubber in the tires is either too thick or too rigid, and to my feel, they don’t bend enough around rocks. Traction is lost that the car really needs. We’ll get to this shortly.

RGT Intruder Wheels & Tires

Chassis and Links

This is a talking point: the rails are 3mm CNC-milled aluminum with a stunning finish. They are really pretty! And the chassis is very stiff, too, thanks to the generous plastic-fiber cross bracing from nose to tail. The shock hoops are part of the rails and even the panhard mount is finished in the same lovely material. Full marks for that.

Links and geometry are also well designed. There’s full movement for both axles, no binding, and plenty of room for everything to move as it needs to. And the car isn’t heavy. These are all great things, too. Honestly, we’re off to a very solid start at this point.

Oh, those links are 6mm stainless steel with stainless steel ball ends, too. It’s so premium. Not everyone will appreciate how nice this is, but as an RC guy with ALL the cars and a lot of experience at this point, I want to emphasize just how high the quality is on this vehicle. RGT have not cut corners on chassis and links.

RGT Intruder Shock Hoops
RGT Intruder Underside

Suspension

The coil-over shocks are also very nice. Aluminum body, thumb-screw adjustable pre-load, appropriately plush springs and intelligently mounted. I like these.

However, my unit arrived with empty shocks. Not everyone will notice this, and not everyone will care, but you want some oil in your shocks. It limits how bouncy they are, which limits how much the wheel reacts to changes in terrain at high or low speed. I’d recommend 30 wt. oil, give or take. Worth doing.

The shocks move well and the car is in good shape with this setup. Just don’t forget the oil like my car’s assembler did!

RGT Intruder Adjustable Alloy Shocks

Straight Axles

No portals here. But the best thing about these straight axles is how tough they are. I love seeing steel universal joints on front steering axles in a crawler. It’s really the only way to go for performance and strength. Yes, they’re not as smooth as CVDs and similar, but the extra steering angle the unis afford you make the trade-off well worth it.

The housings themselves aren’t particularly scale, but the size is small and they are attractive. It’s a high-pinion position like Axial’s AR45 axles and the gears are helical cut (or spiral? Can’t quite tell from the photos). Either way, they’ll be strong, and with the default tooth count of 30/8, overdriving/underdriving using the diff gears for better crawling and steering should be a straightforward undertaking. (I’m confident these will fit, though I haven’t tested them yet!)

RGT Intruder Rear Axle and Links
RGT Intruder Front Axle and Links

Radio & AIO Rx/ESC/Lights

After a couple of vehicles with the new FlySky MGXX-BS radio systems, this is my first one with the middle-spec option, the MG6-BS. It’s a 6-channel radio (4x AAs) and an AIO (All-In-One) receiver, 60A ESC and light controller with discrete light hub for body-mounting. The radio is comfortable in the hand, all plastic, and with two stand-out features/design elements:

  1. Channel 5 is a spring-loaded thumb dial that returns to center. What a perfect controller for a winch! (The chassis and bull-bar have a mount point and fairlead respectively for exactly that, too!); and,
  2. A set of DIP switches on the radio that give you control over drive mode (Fwd/Brk/Rev and Fwd/Rev); LiPO/NiMH; Drag Brake (0%, 25%, 50%, 100% – though it’s weak even at 100%); and all the channel reverse options.

It’s a good system. Be aware the light kit is a cut-down version that gives you headlights or no headlights, and indicators and reverse being always enabled based on steering and throttle inputs respectively.

The biggest drawback is that Reverse is WEAK. Slow and underpowered, it seems to have been a cost-saving choice, as you need less MOSFETs in the ESC for reverse for this outcome. Saved FlySky a buck or two, though you miss it on the trail. Apart from this one drawback, I like the whole system.

RGT Intruder MG6-BS Radio
RGT Intruder FlySky 2A-BS AIO
p

Our Test Course

If you’re not familiar with how we test RC rock crawlers, we have a course that challenges any 4x4 RC crawler in many ways:

  • Approach and departure angle: these  are challenged on Problems 2 and 3;
  • Side-hill ability: tested on Problems 1, 3 and 5;
  • Breakover (skid clearance): tested on Problems 4 and 6;
  •  Suspension articulation and centre of gravity: challenged on problems 2 and 5; and lastly,
  • A punishing ascent on problem 6 tests all of balance, break-over, articulation, tire traction and approach and departure angles.

Put together, we have a gnarly, challenging set of problems that challenge all crawlers. If a rig can conquer 3 or more of them, chances are you have a reasonably high-performance rock crawler. There are some machines that can claim all success on all six in stock form – but not many!

Driving Woes

I tested it on my 6-Problem course. Bad news first: that slow and underpowered reverse is a big enough drawback to be quite noticeable. I also found the steering servo to be slow and it faded under heavy crawling within a few minutes (though it didn’t fail outright).

The motor and gearing is too fast for crawling and too slow for trail driving. There’s no second speed here, so unlike the Rescuer (there’s that comparison again!!), you’re stuck with your gearing, battery and motor choice. This feels just like comparing the TRX4m to the FCX24 with its 2-speed, actually!

The tires are too stiff. The suspension moves like it should, though being filled with oil would have helped. The car is top-heavy and it tips over easily.

RGT Intruder 25kg MG Servo

Driving Wins

On the bright side, this car looks magnificent on the trail. It looks amazing on the rocks. It moves nicely, with plenty of scale body roll without being too much. It’s quiet, and very pleasant to watch it work over the ground.

Without upgrades, in stock form, this will be a frustrating car to drive if you’re going beyond basic obstacles. The waterproofing is a nice touch, as are the lights, but that capability limitation will make itself known regularly.

With upgrades, though? Yeah, I think this could easily become one of my favorite cars. I’ll get back to you on that, as I’m planning on doing all of the upgrades I list below. The car drives okay. Could be better. 4/10.

RGT Intruder Rear-Right

Value Proposition

So, did they pull it off? Is the car worth the asking price? For a bigger, established brand name, the price is good. Although, newer names have been creeping in with very durable and very capable options in recent times – just look at the Ecto if you’re not convinced (review here)!

I think this car represents real potential for the owner who loves the Landcruiser body and has plans to improve it. As a stand-alone crawler, it’s not as good as a similarly priced rig from Element, such as the Sendero HD. But as a scale crawler with potential to go ultra-scale at low speeds, it leaves the more expensive TRX4 and Axial CJ7 in its dust. But those crawlers will be better on the trail with their second speeds, and better on the rocks, with their better tires and overall performance. So, what to do here? Buy it if you love the body, but be prepared to upgrade as you’re able.

RGT Intruder Unclipped Brush Bars

Upgrades?

Open your wallet for this one. I try to be reserved in my upgrade recommendations usually, but this rig really wants a list of things. Ready?

Wheels & Tires

First, the tires need to go. They aren’t great. And since they’re glued, go with a weighted beadlock wheel too. I’m quite partial to the Boom Racing Hustlers – check them out (and I even found some period-correct steel ‘Sunraisia’ style beadlocks that go *perfectly* with this car)!

Also, you’ll want to install wheel wells (I’ll design some soon to download and print).

Electronics

The slow, weak servo needs replacing. Try my favorite budget crawler servo and you can even run it directly off the 2S battery (signal and ground wires to receiver, positive wire to battery connector, via a switch if you want). Or, my fave 7.4v brushless all-rounder is this guy.

While we’re on electronics, the AIO Rx/ESC and motor combo is sufficiently lacklustre that you’ll eventually throw your hands up and slap in a Fusion system instead.

You’ll want a radio system too, in that case – buy a receiver for any other radio you have, or consider the ever-reliable FlySky GT5.

Banggood sells really cheap 6-ch receivers so you can use this handset for up to 20 models, which is handy.

Lights & Accessories

Lastly, lights: use a Y-splitter for the light control module on the throttle channel and hope for the best (I will try to make an Arduino-based adapter for this to piggy-back off throttle and steering channels soon).

Down the track, you may consider a servo winch – the car is certainly ready for one! And perhaps also some scale accessories and you’ll be sorted!

RGT Intruder 35T 550 motor

Bottom Line

It’s a worthy body on a basic car. With upgrades, it’ll be a SWB beast! Without em, it’ll be a bit frustrating to drive. Pick obstacles appropriate to its capability and you’ll enjoy yourself. Just keep the limitations in mind if you’ve got your heart set on this gorgeous model.

My thanks to Banggood for providing RC-TNT with this model to review. I’d have purchased it myself if they hadn’t, because, just look at it! But they made the investment and have my thanks. Grab your own RGT Intruder EX86020 from Banggood here.

RGT Intruder Rear Left
Craig Veness

Craig Veness

RC-TNT

Craig has been into radio control since the 90s and into RC crawling since about 2010, when a Losi MRC started the obsession! Now it's all rocks this and crawl that and upgrade all the things! ...You know how it is, right? Welcome home 🙂

A note on affiliate links: we were provided with this car by the manufacturer for review purposes. The Amazon and AsiaTees links in the above article are affiliate links, which means we may be paid a small commission if you choose to click on them to make a purchase. As always, we make effort to ensure that no review is impacted by this – we still report on bugs and issues encountered during product testing, and our fixes or solutions if found. Thank you for reading and happy RC-ing!

More RGT Articles…

How to Program HobbyWing Fusion RTR ESC?

How to Program HobbyWing Fusion RTR ESC?

April 2024 – various video comments

Redcat Ascent Fusion: How do you program the HobbyWing Fusion RTR ESC? (or, how to program the HobbyWing Fusion Crawler ESC).

HobbyWing Fusion RTR ESC Programming

A. There are three variants of the HobbyWing Fusion now: the Fusion Pro 2300kv, the Fusion SE 1800kv and 1200kv, and the Fusion RTR (aka. Fusion Crawler) 1800kv. It’s the Fusion RTR that ships with the Redcat Ascent Fusion, and we’ll probably see this OEM-supplied unit in other RTR models in future, too.

You can use any of the programming cards from the HobbyWing WP-1080 ESC (and we have a programming guide for all crawlers for the WP-1080 here), the HobbyWing Fusion Pro, or the HobbyWing Fusion SE. It’s the ESC itself that dictates what each menu does, regardless of the sticker on your programming card.

HobbyWing Fusion RTR ESC Programming Menu

First, remove the rubber water shield on the power button module and plug in your HobbyWing programming card. There’s an illustration to show signal, +ve and -ve (white, red and black, in that order).

Press Power to turn the ESC on. The card’s red digits should illuminate. Here’s what each menu item is:

  1. Low-Voltage Cutoff (LVC) for LiPO batteries (1-4; 1 is Disabled (for NiMH batteries), 2-4 is low-high, maybe 2.7v, 3v and 3.3v at a guess);
  2. Motor Rotation (1 CW, 2 CCW);
  3. Drag Brake Force (1-5; 1 is off; 2-5 weak-strong drag brake);
  4. Drag Brake Rate (1-6; slow-fast application of drag brake).

Press Item to cycle through 1 to 4, Value to cycle through the item options, then when you’re done with all of them, press OK to save.

Press the power button to turn off the system.

Unplug the programming card, replace the rubber water sheild, and power up – you’re ready to test!

Craig Veness

Craig Veness

RC-TNT

Craig has been into radio control since the 90s and into RC crawling since about 2010, when a Losi MRC started the obsession! Now it's all rocks this and crawl that and upgrade all the things! ...You know how it is, right? Welcome home 🙂

Yikong 4106 Pro Has a Party Trick!

Yikong 4106 Pro Has a Party Trick!

Inspiration, Not Imitation

Yikong 4106 Pro is a 1/10 RC crawler with an ability we have not yet seen in the RC crawling world. You may not have heard of Yikong before, but they’ve been quietly making some interesting models over 2023 and now 2024. This latest one will knock your socks off, once you consider the ramifications of what they’ve made. But first, some details.

This is a model that combines the best features of the offerings of the likes of Axial’s SCX10 III with 2-speed transmission and DIG (disengages drive to the rear, then locks the rear, for tight turning and improved rock crawling ability) and the Traxxas TRX4 with its remotely activated locking diffs.

4106 Pro Undercarriage

The Killer Feature

But what makes the Yikong 4106 Pro special is something new that we haven’t seen in RC cars ever before: independent disc brakes! They’re only in the rear and they activate via a button that mixes their function with the vehicle’s steering. They work by clamping the inside wheel on a turn, when activated. So, when you turn left, for example, the rear-left wheel is braked, helping to really tighten the vehicle’s turning circle. Genius!

4106 Pro Disc Brake Engaged
4106 Pro Disc Brake Engaged
4106 Pro Rear Axle

On the Floaty Side

The suspension is a bit on the floaty side, with considerable body roll. The vehicle has portal axles, which helps cancel out torque twist while also increasing undercarriage clearance on rough terrain. The shocks are “oil-filled” but the unit I received had “oily” but empty shocks. I’d suggest adding 30wt oil to create some needed damping.

Shocks can be mounted in a variety of positions, which is very welcome. They’re neutral, by default, and I like them there for trail and light crawling. Shock preload is adjustable by thumbscrews, and I found that winding on about 8mm in the rear really helped it with crawling. Now it isn’t so fast to lift a front wheel on steep ascents.

4106 Pro Chassis

4106 Pro Servos

In the below photo, there are three servos closest to the camera. The first two are the diff lock servos, and then the one closer to the battery is the 2-speed servo. These are waterproofed servos with low power, I’m guessing maybe 2-3kg. Plastic gears, plastic spline, that kind of thing.

My front diff lock servo was broken, out of the box. I may replace it with another similarly cheap unit, or I may even just leave it be. I don’t mind the front being locked all the time. It’s the rear one that wants to be able to unlock, both for general driving and so that the ‘tank steer’ feature can work correctly.

The steering servo is a metal geared unit and has plenty of punch. I’m guessing 15kg or so, which is fine for this car.

4106 Pro Servos

Electronics

The ESC and receiver are an all-in-one unit from Flysky, which is OEM-only at time of writing. The Flysky FS-MG11-BS radio system incorporates a connected light kit that is designed to work with the radio system. It manages a lot of complexity in an elegant way. I like it. (It’s the same one you’ll find with the new FMS FCX10 1/10 model, and no doubt we’ll see it in other vehicles soon, too).

The car can take either a NiMH battery (6 or 7 cell), or 2S or 3S lipos. The ESC has a Deans (or T) connector. The power switch is located underneath, behind the skid, and is waterproofed.

The radio transmitter takes 4x AA batteries and you’ll need to supply all the batteries for this vehicle.

The motor is a large, 550-sized can with 32 turns. It’s well suited to the vehicle and I like it on both 2S and 3S.

4106 Pro Power Switch

Axles & Undercarriage

Axles are a pleasing scale design, with smooth lines and bolts in the right places. They engage well, seem like they’ll be durable, and the portals are tastefully implemented. No hulking, unnecessary chunks of plastic here. The front axles are steel universals, adding to their strength and something I always want to see in a crawler.

Thoughtful design is what you’ll find underneath the vehicle. Stainless steel links and inverse-rotation drive shafts are also like this. There’s a servo saver in the form of a passive steering damper on the steering link, too. It’s a solid undercarriage, overall. Nothing is hanging down to be grabbed by sticks or rocks and it just looks good.

Now, you may have read that it has a molded plastic chassis instead of the usual steel stamped C-channel rails. This is true. But, it works. The car is lighter for it, flex isn’t a huge issue and it keeps the cost down. I don’t see a down side in this model with that choice.

4106 Pro Steel Unis
4106 Pro Front Underneath
4106 Pro Body Screw

Mercedes & Hyrax: Clone Wars

The wheels are 2.2″ and look like the real thing, with the tiny Mercedes G-Wagon spokes around a solid wheel hub. The tire treads are not so scale, being a Proline Hyrax clone, but run on a 4.56″ tire carcass, which Proline does not make. Not entirely a clone, then – though the treads themselves clearly are Hyrax. The foams are a little on the firm side but they work well.

4106 Pro Tires

A Mysterious Interior

This G63 body has a complete interior, including dash, steering wheel, dash details and shifters, seats front and rear, and nicely finished. It’s in moulded polycarbonate, keeping the weight low.

However, there’s been a weird decision to apply a frosted, semi-opaque paint layer to the inside of the body on the windows, making it possible to only see the blurred outline of the seats, at best. Why go to the trouble and expense of including an interior, only to hide it? Perhaps subsequent manufacturing runs have removed the paint from the windows. I hope so.

Yikong 4106 Pro Body
4106 Pro Bendy Mirrors

Front Bumper Dilemma

The car comes with a solid plastic front bumper that can be installed. By default, it is not installed, instead allowing the stock polycarbonate body to show off its pretty, moulded front lower grille. If you want to install that front bumper, some of the body needs to be cut away to fit it. I was going to do this on mine but realised it would look worse. Cutting it is a one-way decision, so I’ve decided to keep mine as it is.

I should also add a note here about the sliders. They look like the aluminum of the real car -that is to say, they’re molded and painted on the polycarbonate body here. That means they look great, but it also means they’re weak. Just like the real thing, they’re really just for looks. You could beef it up with steel or plastic underneath, but it would be a custom job. As far as I know, there aren’t after-market rock sliders available for this model (yet).

4106 Pro Under Body
4106 Pro No Sliders

Lighting Up the Trail

The body also enjoys a complete light system. It functions as part of the integrated Flysky receiver/ESC/light unit and provides full-function lighting. Low beam, high beam, flashing, indicators, braking, reverse, and fog lights are all part of the vehicle’s abilities. Looks great and you can switch between off, low, high, and flashing configurations.

4106 Pro Light Kit

Drive Modes

Also part of the Flysky system is a set of DIP switches on the radio transmitter. Switch 1 toggles driving mode from Fwd/Brk/Rev (trail driving) to Fwd/Rev (crawling). In the Trail mode, the taillights increase red luminosity when braking. In Crawl mode, there is no braking; you simply see the white Reverse lights when reversing, and the low-glow red taillights when otherwise stationary or driving.

Speaking of the transmitter, the wheel feels very premium. There’s a weight to it, though plastic, that has the feel of a much more expensive radio. The spring is light, the balance neutral, and it just feels great to use. The throttle trigger also has a pleasingly light action.

4106 Pro ESC

Radio Freedom

There are many options on this radio and happily, many are not used. There’s a thumb dial that has maybe 5mm of movement from neutral in each direction – that isn’t populated on the receiver, so it’d make a great winch controller or rear steer option.

On top, there’s a button and a dial that also aren’t used on the receiver (unless mixing interferes with this; I haven’t tested them yet), but you end up with quite a few options. You could put a sound system in the car and have the spare top button as a horn, for example.

Yikong 4106 Pro Radio Side

Drag Brake on the Fly

Lastly, the radio also gives you a dial (Ch.11/Drag Brake) that allows the drag brake rate and intensity to be adjusted on the fly. The maximum setting feels like the equivalent of about 70% drag brake on a WP-1080 ESC (incidentally, see our programming guide here), in this vehicle. The minimum setting is basically zero drag brake. My video review shows the difference between these on the steep rock descent near the end. It’s a nifty feature.

Yikong 4106 Pro Radio Top

Yikong 4106 Pro Driving Dynamics

The car drives quite nicely. This is a scale vehicle more than a performance machine. With it’s many driving accessories, it’s very fun to play around with. The two-speed transmission has a pleasingly wide ratio between first and second. The lockers engage nicely – well, I should say, the rear one does.

The front one does too, when I do it manually, but my front locker servo arrived faulty, so I can’t tell you from experience. I’ll swap mine out for a replacement servo (just a mini size, they’re pretty universal, so no worries there) and it’ll be fine. The so-called ‘tank turn’ feature of those rear disc brakes is just fabulous, and the lighting kit in the pretty body makes night driving possible and day driving more scale.

4106 Pro 32T 550 motor

Back to the Big Thing

Now, onto those ramifications I mentioned in the intro: independent disc brakes. Yes, this model uses a single servo to modulate between left and right, for the sole purpose of tightening your steering radius when active. It works well. But as a proof of concept, now we know disc brakes work and that they can be rugged enough to be effective in an active, wet-n-dirty off-roader. On its own, that’s already impressive, right?

4106 Pro Disc Brake Servo

Now Think BIG

Okay, now think about faster cars. The Arrma Infraction has a disc brake on the rear outdrive from the transmission, for example. (Incidentally, buy an Infraction using this link for a discounted purchase; it’s my all-time favourite street car and so very worth it). Already a super fun, super powerful street machine, you now effectively have a hand brake feature on an 80mph-capable street basher. Nitros have also been using a disc brake on the drive shaft for years.

But to have disc brakes independently on each wheel? This means the traction control of full-size cars can be brought into road and track RC cars! Do you see the potential here? We already have the technology in the tiny ESC modules of current RC vehicles. Add a few extra servos and now you have something that can brake each wheel as traction is lost in a corner or under acceleration, and so on. What an exciting idea! I don’t know of any other manufacturer currently doing this, but I’m hopeful and excited to see more. Wow!

4106 Pro Brake Mechanism

Final Thoughts

Frosted interior windows aside, the Yikong 4106 Pro is very well thought out. A manual would be appreciated, especially for hobby newcomers, as there’s a LOT going on with the radio. Thankfully, it’s well labelled.

I don’t support the blatant IP theft that Yikong have seemingly undertaken from Mercedes with the pretty G Wagon body, nor from the Hyrax tires. But, on the whole, they’ve created something special.

I’m loving the progress we’re seeing from these smaller brands and I’m so pleased the Yikong 4106Pro is not just another clone of an existing vehicle. It’s fun to drive, capable for what it is (think ‘Class 1 comp crawler’ and you’ll be pleasantly surprised) and it looks great. Recommended.

4106 Pro Steering Damper

Where to Buy

Here’s where I bought mine (not an affiliate link; it’s just the only place I could find it in stock in Feb 2024). There’s another Yikong model on my ‘to-buy’ list, but it’s a bit bigger than this one! Check out the Yikong 4083 1/8 RC crawler here.

Yikong 4106 Pro Rear
Craig Veness

Craig Veness

RC-TNT

Craig has been into radio control since the 90s and into RC crawling since about 2010, when a Losi MRC started the obsession! Now it's all rocks this and crawl that and upgrade all the things! ...You know how it is, right? Welcome home 🙂

A note on affiliate links: we purchased this vehicle ourselves for test & review purposes. Some of the links in the above article are affiliate links, which means we may be paid a small commission if you choose to click on them to make a purchase. As always, we make effort to ensure that no review is impacted by this – we still report on bugs and issues encountered during product testing, and our fixes or solutions if found. Thank you for reading and happy RC-ing!

Losi Super Baja Rey 2.0

Losi Super Baja Rey 2.0

It’s Huge

The Losi SBR 2.0 is one of the larger RC cars available today (currently on sale here). But it’s also quite different to most of the other 1/7, 1/6 and 1/5 scale fare you can choose. It might be the most unique offering in this scale, now I think about it. Consider: if you want to bash hard, you buy an X-Maxx, Outcast 8S or Kraton 8S. If you want to crawl or trail drive, the SCX6 has you covered. Large scale race track nearby? Get yourself a Losi 5IVE-T 2.0 or a DBXL and have at it. HPI’s Baja 5B has you sorted for big buggy action.

But what if you want scale desert truck driving? Humungous suspension travel, the kind of cornering that only a live rear axle can deliver? Something to match the Traxxas UDR favored by so many? But… bigger and more aggressive? Losi has you covered with the Super Baja Rey 2.0. Let me show you what makes this enormous monster so special.

Losi SBR 2.0

This is a 1/6 scale desert truck. I didn’t have the original one, so I can’t give you a side-by-side comparison, but Losi says this one is built on the Super Rock Rey chassis, but with an extra inch of wheelbase length. They’ve combined it with the front of the Super Baja Rey and there you go, SBR 2.0.

It’s a four-wheel drive vehicle that is engineered to be tough – but of course, with the live rear axle, it will take the right driving approach to keep the wheels on the ground. This style of vehicle is made to soak up big bumps at high speeds. While they can slide and corner reasonably well, this will never be a basher to replace the likes of the Arrma Senton 6S or similar, with its independent front and rear suspension. I guess you could say that RC desert trucks – the SBR here, the BR2.0, Traxxas UDR and so on – are all about the scale drive.

Losi SBR 2.0 Front LHS Corner

Body Issues

I’ll start with something that was a bit of a let-down. It’s only minor, but this isn’t a cheap model and so you expect the thing to be pristine out of the box. For this design, Losi elected to use something like vinyl wrap for the livery. Mine was a little worse for wear, with cracks in the decals around folds and edges. Some sheets were even misaligned. Screws were oxidized and there’s dust under the light bar lenses.

To be fair to Losi, this is surely a challenging model to assemble. Even in a production-line style setup, I expect it would take considerable effort to get something like this together without mistakes. But to find so many minor issues with my unit does make me wonder about quality control. Is it only the body I should be concerned about here, or will there be missing grease in diffs or a critical screw not secured completely?

Still Gorgeous Tho

The issues I had with this thing are only skin deep, as far as I can tell. At time of writing, I haven’t run the car yet, so if there are underlying mechanical oversights, I’ll edit this section later to let you know. But if you’re not looking closely, those misaligned panels and livery sheet cracks are not obvious. It’s all forgivable when you step back and take the thing in. This is a machine of beauty.

Radio System

Cars rarely came with radio systems in decades past. However, relative to RTR (Ready To Run) sales, kit builds are a lot less popular than they used to be. Many hobbyists may still prefer a kit (including me), but it isn’t what sells. Instead, manufacturers are typically now releasing models with everything assembled and included. The included radios with RTR systems have been hit and miss, maybe more on the ‘miss’ side for some time.

Horizon Hobbies has several big brands under its umbrella at this point. This includes the Losi vehicle here, but notably, also Spektrum. This is why you’ll get a Spektrum radio and power system with most Horizon-brand RTR models these days (Arrma, Losi, Axial, and so on). While the common and more basic Spektrum SLT3 system is fine, the better one is the Spektrum DX3 with 6100AT AVC receiver – and that’s what comes with the Losi Super Baja Rey 2.0.

I like this system in particular because of two dials that make it so much easier to use than so many others. The first is an adjustable braking dial – turn it up for more aggressive braking. The second is a stability control dial, or steering gyro – turn that up to have the car counter-steer more responsively to keep the nose pointed forward. In a car like this, I’d suggest the former is quite important and the latter is probably best left turned mostly down. Experiment and see; it’s so easy to adjust on this radio. I’m a fan! (The marks and dust are because Metro Hobbies sent me a floor model without telling me. Disappointing, but not a big deal).

Losi SBR 2.0 Spektrum DX3 Radio

The Main Thing

This is what we’re here for: that epic, desert truck suspension and live rear axle. Check these pictures out! Look at how much range there is, especially over the rear axle. It’s plush, heavy-duty and epic. Of course, the rear suspension is mounted on trailing arms, and everything about the arms at both ends is heavy duty and well designed. There are hefty sway bars at each end and it looks great. Even just typing this, I’m wondering how I’ve managed to not drive this car yet. I’m busy, but too busy to drive this car? I’m selling myself on this thing just writing this.

The front end has plenty of travel as well and the body has a pleasing amount of roll. There’s bolstering around the chassis mounts and both ends are adjustable with alu thumb screws. Looks great, too.

Drive Line

Steel universals are found throughout the vehicle’s drive line. The rear shaft is a fibre-infused telescoping unit that attaches to the steel unis at each end. Given the crazy power this car can make (and we should talk about that in a moment, see below), you’d reasonably question if plastic will be up to the job on the rear end, in particular.

Well, there are steel drive shafts available on the after-market for this car, but having discussed this car with other owners, the consensus seems to be that it’s tough enough for the job. Certainly, there’s not a lot of flex in the parts, but rigidity is probably the more important element here. The glass element should be sufficient. We’ll see!

Losi SBR 2.0 Rear Shaft and Links

Wheels and Tires

BF Goodrich Mud Terrain T/A KM3 tires are clamped securely in Method Racing beadlock wheels on 17mm hex adapters. Side walls are firm but have some flexibility and the foams are also medium-hard. Of course, there are the two full size, functional spares on the rear of the vehicle, which is part of the magic of this interesting car.

Power System

Bigger numbers don’t necessarily mean bigger speed. With RC power systems, getting the voltage, motor kv (revolutions per volt), and gearing correct can be a balancing act. Typically, larger scale vehicles will run lower kv motors, favouring higher volts to achieve the torque and power required to move a heavy vehicle rapidly.

The SBR 2.0 runs a Spektrum Firma 160A 8S-capable ESC, powering a hefty (no, really) 5687 750kv motor. This is both a huge diameter and lengthy can – this motor is 56mm across and 87mm long.Batteries are loaded from the bottom of the vehicle, also helping to keep the weight low. It has a claimed top speed of around 50mph. Doesn’t that sound kind of uncomfortable! Fun, though!

Losi Super Baja Rey 2.0

How does it drive? Well, I can’t give you that quite yet. I’m looking forward to it, but I’ve been waiting to drive with a Traxxas UDR so we can compare them a bit. I might try to throw in an Arrma Mojave 6S as well, and then we can see which might be the best to get for your purposes. I’ll put that video here, when I make it. I can’t wait!

Read more here and buy your own Losi Super Baja Rey 2.0 here.

Losi SBR 2.0 Front LHS

Don’t Miss

Meanwhile, you might be interested in reading about the 10-car roundup we’re doing at the end of 2023 and into early 2024. There are ten short course and desert trucks in 1/10 and 1/8 scale from all the big names and some of the smaller ones. The list includes the new Tekno SCT410 2.0, the Losi Baja Rey 2.0, Arrma Mojave 4S as well as the Senton 3S BLX, and more. Check out the channel for more.

Craig Veness

Craig Veness

RC-TNT

Craig has been into radio control since the 90s and into RC crawling since about 2010, when a Losi MRC started the obsession! Now it's all rocks this and crawl that and upgrade all the things! ...You know how it is, right? Welcome home 🙂

A note on affiliate links: the Amazon links in the above article are affiliate links, which means we may be paid a small commission if you choose to click on them to make a purchase. As always, we make effort to ensure that no review is impacted by this – we still report on bugs and issues encountered during product testing, and our fixes or solutions if found. Thank you for reading and happy RC-ing!