Introducing the GMade BOM TC GS02F
GMade BOM TC GS02F Builder’s Kit
Meet the GMade BOM TC GS02F, a builder’s kit 1/10 scale RC rock crawler. In the world of RC rock crawlers, there are ready-to-run (‘RTR’) models and there are builder’s kits. RTR vehicles generally come with everything except the batteries. Meanwhile, kits require you to supply the radio system, steering servo, ESC (Electronic Speed Controller) and sometimes the motor.
Both RTR and kits give you essentially the same finished product. Kits come with a possible learning curve and a time investment up-front. That investment yields satisfaction for a job well done at the end. I open with this thought because the GMade BOM TC (GS02F) is a builder’s kit. It requires you to get the tools and electronics onto the workbench before you can enjoy this refined machine. You’ll need to supply your own radio system, motor, ESC, steering servo and transmission servo (to shift between first and second gears for low and high speed).
Because a kit build can be a deal-breaker for some, let’s get this part out of the way first: having recently built one myself, this was one of the most enjoyable builds I’ve done, and that’s from dozens of builds over the years.
Beauty and Brawn
The GMade GS02F BOM TC is a 1/10 scale RC rock crawler with a truggy body. It was the first 4X4 crawler, either kit or RTR, to finish all 6 closed circuit test problems, and in stock form! Clearly, rock crawling performance is a great strength of this special truck. If you haven’t enjoyed kit builds in the past, or even if you’re new to them, this is a pretty nice starting option. The only build I remember doing in any recent years that was easier and/or more fun than this was the Traxxas TRX4 Sport (see our video review series here on RC-TNT for the Sport).
The GMade BOM TC GS02F Kit Build
Everyone has their own preference when building an RC model. I personally like to start with painting the body. Whilst this isn’t overly difficult or time-consuming, it’s something I don’t particularly enjoy. My preference is to get it done and out of the way, so that I can then enjoy the mechanical assembly process. This way, I know that when that’s all done, the truck will be ready to go!
Body: Paint and Trim
Speaking of the body, it’s only a half body to be painted: just the cab and hood, really. The truggy bar work on the rear half just go together as part of the assembly process. For my unit, I chose a nice blue with some maroon and black lines to break it up. I finished it with one of the white door panel stickers that was included in the kit. A windscreen banner sticker and some rear window and door panel branding and it was done!
Body: Front Grill
If you want working headlights, the front grill needs cutting out. The chromed plastic grill and light bucket trim fit into the hole. This is secured with double-sided tape. Alternatively, a sticker is optionally included to place along the uncut front instead. This means you don’t have to have headlights if you don’t want them. For a comp truck, this would be the way to go – but I went with the chromed plastic. It looks great!
The included stickers for the body are too thin and allow some light and colour through from the body. They should be a bit heavier to make their own colours more vibrant and less transparent. It’s not a big deal but good to be aware of when planning your paint scheme.
The mirrors attach with an alignment hole and one screw further down and are secure like this. However, if you’re going to be rock crawling primarily, consider removing them to help preserve the body. Otherwise, they will eventually be snapped off or will damage the polycarbonate body where they’re mounted.
Body: Truggy Bar-work
GMade has designed a lightweight but strong and flexible rear bar assembly for the truggy body of the GMade BOM TC GS02F. It looks good in black and had suitably strong but small screws throughout. The bar-work nicely compliments the body front half of the body. It incorporates a faux fuel cell which is just an empty, plastic box, but it looks right at home where it’s placed, centrally in the bars.
The bar work also includes a clever pair of hinged arms that insert into the rear chassis bumper cross-member. This allows the entire body to then hinge open and closed, secured at the front – through the hood – with two body clips. It’s functional, looks great and is strong enough to outlast the rest of the vehicle. …unlike another component, but we’ll get to that in a moment.
Overall, it’s a very pretty crawler. The body is light-weight, which is important for crawling performance (see our video that tests this very claim). The competition style bull bar compliments the chromed grill and is strong but lightweight. The bull bar is pleasingly flexible like the rear bar work. The whole body looks fantastic and I’m very happy with it.
GMade BOM TC GS02F Driveline
The front and rear drive shafts are arranged in a straight line, minimising the wear on the universal joints at each end. It’s only a very minor gain, but this helps minimise energy loss/maximise efficiency of the drive system. It’s a welcome design. Another sweet little feature is the front & rear shafts spin in opposite directions. This effectively cancels out the torque twist experienced in other models without this design feature.
Torque twist is the phenomenon of the vehicle twisting in the opposite direction to the drive shafts when the vehicle is under acceleration. It inhibits suspension movement, particularly in the rear, resulting in a crawler that is less sure-footed on rocks and more prone to tipping on steeper terrain. By having the front and rear shafts spinning in opposite directions, this torque-induced twist is cancelled out. Just another thoughtful design decision that adds up to this rig’s outstanding performance! (Can you tell how exciting this is for a hobbyist yet?)
Transmission & Ratios
The transmission is a tidy, one-piece unit. It incorporates the motor mount at the front, opposing-direction output shafts (per torque twist elimination, as above), overdrive gearing options of 0%, 14.29% and 22.22%, and a two-speed selector with integrated standard servo mount and arm. It’s an updated design that replaces the weaker GS02 implementation. The GS02 mated the top half of the transmission down onto the skid plate, which used to house the gears. It was a weak design, prone to lifting and breaking. It’s good to see manufacturers working toward improving their designs and the GS02F is a great example of incremental improvement of this nature.
The motor’s pinion gear meshes with the bigger gear, called a spur gear. The assembly features a dual slipper clutch. This just means there are slipper pads on each side of the spur gear for greater longevity and less need to tighten the slipper as it wears. When you first set it up, I’d recommend backing off just a quarter turn from maximum for crawling or a third of a turn for a trail rig.
The transmission features overdrive gearing, which spins the front wheels 14.3% faster than the rear wheels. This assists in tightening the vehicle’s steering circle and especially can help when negotiating difficult rock problems. Overdrive helps the rig to follow where you’re pointing the front wheels. It’s a common engineering approach for rock crawlers that is often achieved by changing the ring and pinion gears in the diffs to get the speed difference, so to be able to have overdrive from the transmission instead means the diffs can retain their strength with full-size gears. Another great little bit of thoughtful design!
GMade BOM TC GS02F Diffs
The GS02F diffs are the let-down for this otherwise stellar performer. The diff gears are made with a cast manufacturing process. Casting is cheap and useful for many things. But diff gear teeth are subjected to significant stress in a rock crawler and the better solution, though more expensive, is to make your gears by cutting a hardened steel block.
A decade ago, most crawlers had cast gears. In the 2020s, the norm is now hardened steel – and even the GMade here uses cut steel gears in the transmission. It’s such a shame GMade went with the cast process for the diff gears, as they’re considerably weaker in comparison to hardened steel. Our test unit took this damage after 90 minutes of driving. In the picture, the left ring gear is the new replacement while the right is the damaged ring gear – the bigger gear in the diff.
I’m not currently aware of any after-market option for hardened steel diff gears for the GMade BOM TC GS02F. If this changes, I will update this article if/when this becomes available. It’s a big deal, as it is the one factor that keeps the BOM TC from being the best mass-produced RC rock crawler of its type ever produced, from a performance perspective. It really is that good. Such a shame for GMade to get so close, only to be let down by these gears!
GMade BOM TC Axles
The GMade GA44 axle is a single-piece injection-moulded plastic part. It features an up-angled metal diff cover and a rounded pumpkin bottom to help the vehicle slide over rocks. Indeed, the entire undercarriage is designed with this in mind. The kingpin angle is set to minimise tire scrub at full servo throw and the high-steer arms on the knuckles assist with clearance. Castor angle is adjustable, but the stock setting is just fine.
The middle of the diffs feature a cast metal locker. This is one place where cast metal is completely acceptable. If only the diff gears were not cast, it’d be perfect! The constant velocity axles are sufficiently strong and there’s a 45 degree zero-ackerman steering system, as is standard in crawlers these days.
Motor & ESC
This brings us to the logical question: is the GMade BOM TC any good even with the weaker diffs? Well, yes – as long as you fit an appropriate power system. In my test video I started with some premium gear, with the Holmes brushed ESC and 40T 540 Expert brushed motor. I ran it on 4S (14V), before I realised the diff gears were cast. After the initial review, my subsequent driving was done on 3S LiPO instead of 4S (that’s 11V nominal instead of 14V). This should have been okay, but even so, with the punchy 3-slot Holmes motor, it proved too much and the gears broke.
My recommendation at this point is to run the GS02F with a 16T or 20T 5-slot (or 5 pole) 540 motor. For ESC, consider a HobbyWing WP-1060 or WP-1080. Running a 3S (11.1V) LiPO battery will be fine with stock gearing, as long as you have a 5-slot motor. Or, if you end up with the more common 3-slot motor, say, a 35T or 45T 540, stick to 2S (7.4V) for best results. Remember, you still have a two-speed transmission so higher wheel speed, albeit with reduced torque, is only a button press away.
The GS02F will fit a 540 or 550 motor. The chassis includes a cooling fan bracket as part of the bracing between the front suspension towers. The front-mount motor helps with forward weight bias, which we’ll discuss more in Geometry, in a moment.
The battery tray sits in a horizontal position over the top of the transmission, behind the front wheel arches. Because the motor is up-front, the battery tray can be nice and low. This helps keep the COG (Centre of Gravity) nice and low. As I assembled the model and observed these thoughtful features, my anticipation of this being an able performer grew and grew. Read on and you’ll see just how good it really was in testing!
GMade BOM TC GS02F Wheels
When you see ‘1.9” wheel’, this refers to the diameter of the wheels. Likewise, when you see it for tires, it means the inner diameter, where the tires meet the wheel. Most 1/10 scale rock crawlers have 1.9” wheels, while some have 2.2” (eg. Traxxas TRX6) and some have 1.55” or 1.7” (eg. RC4WD Trail Finder 2).
The wheels have a standard 12mm hex mount and a 0.5mm positive offset. This means they’re fairly standard and will fit just about any axle. They’re 23mm wide, single-piece plastic and have a ‘holeshot’ design. The major note here is that they are not beadlocks. This means the tires would need to be glued to the wheels for them to work with this crawler. It is strongly recommended you don’t ruin the lovely tires with CA glue (which is the correct compound if you are on a super-tight budget and do end up gluing them). Far better to shell out another $40 or so to buy a nice alloy set of beadlock wheels. Beadlocks will clamp the tires in place and add a little extra weight down-low as a bonus.
GMade MT-1904 Tires
That’s the wheels – largely not worth using. However, the tires are another story. The GMade MT-1904 1.9” M/T Off-Road tires are excellent. In our video review series, these tires were the best performer of 12 different sets tested. That’s a big deal! These are great, just with the stock foams! By all means use them – just get yourself some beadlock wheels and you’ll be all set.
The MT-1904s are 121mm high and 45mm wide, with the inner diameter of 48mm (or 1.9”, as explained above). They’re great, enough said.
- Width : 240mm
- Height : 226mm
- Length : 515mm
- Wheel base : 313mm (adjustable to 324mm)
- Ground clearance : 77mm
The GS02F chassis allows adjustment of the wheelbase between 313mm (stock) to 324mm, accommodating some larger bodies. Optional link kits are sold separately, but the default 313mm length will fit the most common bodies – including the one it comes with, of course!
The chassis is a steel ladder frame, powder-coated, with C-channel sides. The cross members are hex-bolted plastic. The entire assembly is quite rigid and still reasonably lightweight. Inner fenders are a nice added touch, helping keep debris from out of the interior whilst adding to the scale finish. You get a front and rear set of fenders, but as it’s a truggy body, you’ll only install the front set in stock configuration.
GMade GS02F Suspension
The front suspension is fairly standard for modern crawlers. They’re big bore, aluminium, oil-filled shocks with coil springs and finger-adjustable pre-damping.
The rear suspension is something a bit less common and rather special. They’re coil-sprung, oil-filled shocks in a cantilever assembly! They work very well and allow vertical space for custom bed bodies and full-size body interiors. Best performance is still found with traditional upright, full-size shock assemblies, but as far as cantilever implementations go, the GS02F unit is a decent performer. The trade-off for added flexibility and slightly better COG is worthwhile here.
Links are 5mm stainless steel with solid injection-moulded rod ends and stainless steel ball ends. They’re lightweight and sufficiently strong. They nicely match the lovely, smooth undercarriage and rounded diff pumpkin bottoms very well. The rig slides over obstacles ever so smoothly. It’s an excellent all-round design.
There’s 4-link suspension in the rear and a 3-link/panhard and CMS (Chassis Mounted Servo) arrangement in the front. This rounds out a poised and well-sorted chassis and suspension package.
BOM TC Steering
The Gmade BOM TC steering system has the steering servo mounted to the chassis, in imitation of real life. It’s not a zero-bump steer setup, but it’s pretty close to it. This means the steering does not affect the position of the wheels relative to the suspension. You end up with a nice, laterally-stiff geometry that results in precise steering. Again, this is perfect for rock crawling performance and is something that many crawlers with chassis-mounted steering are noticeably lacking. I wish more crawlers were designed in this way!
The panhard bar is nicely tucked out of the way also, so the steering and front components are all able to function nice and independently of each other. It allows the components to work together unhindered. At risk of sounding like a broken record at this point: it’s such a well thought out rig!
GMade BOM TC GS02F Weight
The model features a forward weight bias of about 55%, which is about right for general purpose rock crawling. This helps with getting traction down through the front wheels, helping the vehicle clear over obstacles even on uncomfortable tilt angles. You wouldn’t want it much more forward than about 60% generally. Forward weight does help with ascents, but severe forward weight bias will bring everything unstuck on the way back down an obstacle! In my competition and hobby experience, 50/50 to 60/40 is a good general range to work within, so the GMade BOM TC falls right in the happy median there! Perfect.
GS02F Trail Performance
Though this is a glowing review for the most part, be aware that the GMade BOM TC GS02F is not the ideal trail truck. Its stock overdrive setup is actually a drawback if you’re looking for a trail truck as opposed to a rock crawler. You can optionally set 0% overdrive in the transmission with different sized idler and drive gears. However, for the same price as this kit you’d be better considering the Traxxas TRX-4 Sport, which will be more durable and better suited as a go-everywhere, low-speed bash truck.
Don’t buy this if you’re looking for a trail/casual play machine. There are better options: the TRX4 Sport in kit form, as above, or the Redcat Gen 8 V2 in RTR form. Both will be more durable and arguably less maintenance for general trail and bashing.
GS02F Rock Performance
Rock performance is where the GS02F shines. It may not be an ideal trail rig, but diff strength aside, the GMade BOM TC is THE best performing 4X4 RC rock crawler (in stock form) ever tested at RC-TNT. This is not an easily-earned title. We have a playlist that covers this impressive machine, warts and all. Check it out here.
All Weather & Durability
There are a few factors where wet running are concerned. The electronics are your responsibility in a kit build, for a start. If you buy waterproof servos and ESC, you’re largely set. The radio receiver box has excellent water shielding built-in, which you can further enhance with the use of silicone grease after you’ve installed the receiver. Even without the grease, it’s a well-designed box that will keep water out for everything short of submarining the truck. Of course, this is something you could get away with, but probably shouldn’t try!
Bearing Up Under Pressure
Where the GS02F falls short for wet running is its bearings. They’re naked/unshielded, which means if they get wet, they’ll lose some of their grease. If they get wet and at all dirty (and lets face it, even light dust would do it), they’ll run rough and then seize before their time. If the weak diff gears are the vehicle’s Archille’s heel, the unshielded bearings are a near second where weakness is concerned.
Consider a Plaig, Fast Eddy, Boca Bearings or other brand of after-market, all-weather/water-resistant bearings for this build. You’re looking for ball-bearings that have a rubber shield on each side, helping keep the grease in and water and dirt out. That’d be $30 well-spent at time of build, else plan on replacing at least some bearings after a few hours’ runtime, as even light dust will eventually make its way into the bearing races. Not ideal for a crawler – GMade can do better on this point and hopefully will in future.
Unshielded ball bearings and cast diff gears aside, the GMade BOM TC GS02F is an absolutely exceptional machine. It’s lightweight and has a gorgeously flat undercarriage. Its components are well thought out in nearly all elements and it’s a joy to drive. Coupled with the right power system (ideally a 5-slot 16T brushed motor) and used primarily as a rock crawler, this rig will leave competitors in its wake. It will just impress and perform wherever you run it. It is the most capable crawler of its class in stock form we’ve tested to date! This is a title not easily earned.
If you’re rough with your toys and want something you can drive everywhere, no matter the weather, and something that’s tough enough to go the distance, you might instead consider the Traxxas TRX-4 Sport. Or, on the cheaper, RTR end, the Redcat Gen 8 V2. We’ve got a helpful article here on the best rock crawlers to consider.
However, if you’re into RC rock crawling in particular and appreciate a well-designed rig that excels with finesse rather than brute power, you will find the GS02F one heck of a contender. It’s really, truly good.
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 🙂