LEGO Technic 42139 All Terrain Vehicle – A vehicle that really does have it all [Review]

The LEGO Technic theme is all about the fun of engineering, and what’s more fun and filled with mechanisms than a utility vehicle? But not another tow truck or crane or piece of construction equipment. No, we’re talking about the LEGO Technic 42139 All-Terrain Vehicle! It’s about time we’ve had a solid-sized ATV in the Technic lineup! So let’s not beat around the bush. Instead, let’s hit that throttle and get in the thick of it! Come along with us as we build and test this 764pc model’s many features. It just became available today, and retails for US $79.99 | CAN $99.99 | UK £64.99.

The LEGO Group provided The Brothers Brick with an early copy of this set for review. Providing TBB with products for review guarantees neither coverage nor positive reviews.

Unboxing the parts, instructions, and sticker sheet

The front and back of the box are standard fare. The back shows that there are multiple moving parts to the build, and there’s not even enough space to draw attention to the winch.

Inside are 5 numbered bags 1-3, an unnumbered bag for the wheels and tires, and of course the sticker sheet and instructions.

The instructions are considerably thick for a 10+ build, but understandably so, as this thing is so packed with features. We all have our opinions about stickers, but I personally find these ones look pretty cool! They also seem to feature Easter eggs, with the branding “Taki” possibly referring to LEGO Technic designer Samuel Tacchi. My guess is “Sullivan” refers to the graphic designer who made the stickers.

The build

And now we’re off to the races! Or woods, perhaps… We begin the build in the center with our first moving element, a 2 cylinder engine block.

A changeover clutch is added to allow for high and low gears, in addition to a neutral. The difference isn’t drastic though, with a 20-tooth clutch to a 12-tooth bevel gear (5:3) on one side and a 16-tooth clutch to standard 16-tooth gear (1:1) on the other.

Next we start to add our frame, including our first pivot joint, or sort of pass-through coupling. This small turntable will connect the wheel sections of the ATV while allowing for variable suspension.

There would be no way to make the engine switch gears if we didn’t have a changeover catch, so next we add that to the model.

After that, it’s time to add the beginning elements to our winch system. A little catch mechanism is created to keep the line secure, and it’s accomplished with a small rubber band. You must press a lever to pull it out, and it makes a satisfying ticking noise when you reel it in.

The catch has two 12-tooth gears – one for the catch itself and one for you to hold onto to twist the mechanism. The rotation is transferred 90° via another 12-tooth bevel gear so that it can span the distance to the front of the vehicle. There, a pair of 12 and 20-tooth half bevel gears return things to their original orientation. The reel for the winch string is eventually cradled between a pair of 3×5 Technic triangle beams (I like to call them “coat hangers”), which also help to guide the line.

Next up is the steering. It’s a pretty straightforward and old-school setup. Instead of using a gear-rack, it’s a simple pivot linkage, but it works well here. Knob gears help stabilize the body while allowing for the necessary range of motion.

That brings us to the suspension – the reason for all the fancy connections and unique drive train. At it’s core, it’s just a simple set of shock absorber springs on a frame. There will be two of these, and they allow for a decent degree of movement.

Now things get really exciting as we add in the differentials and second coupling! We start off fairly straightforward, but it’s certainly meaty!

It definitely gets more busy once we add in the second differential, though! There is a lot going on here, but basically it allows all the wheels to work independently, at all sorts of vertical angles (within the constraints of the suspension). It does not, however, move horizontally, from side to side like an articulated body.

Something odd to note here is that the instructions are very confusing on the page of the book where you add the second differential. You have to line up the parts just right, which is a little difficult in itself. But it’s made confusing in that the cutout picture that’s supposed to give you a closeup overhead shot is actually flipped over (or looking from the “underside”). It doesn’t match the orientation of the model in the main picture.

After getting past the confusing stuff, we head back to something easier – making the structural components of the back end. I like the aesthetic detail of using dark grey telephones on this section.

We’re not finished with mechanisms yet, though! We return right back to a (much simpler) dump rigging for the cargo/utility bed. The action is smooth, with just the right amount of tension – and lots of fun to fiddle with.

Flipping that over, we now add our second set of suspension springs. (Say that 5 times fast!) The range of motion may not seem huge, but it’s pretty decent for a model of this size.

Switching back to the winch (front) end, it’s time to put on the guard bars. The angles on the front bars look particularly nice. Additionally, we finish the body off with the hood and fenders. This is the point where we really pour on those stickers.

Both switches for the winch and the shifter are found on the same side, labeled. The decal print does get a little weird on this one, though, and looks like the sticker is damaged between first and neutral.

We finish up the front end with the handlebars. I’m a fan of the fact that they included the brake handles and in general it looks pretty good, but there’s a small part of me that thinks it feels unfinished. Perhaps some bush elements in the axles would make the grips feel more complete, maybe?

As we approach the last few steps, we revisit that utility bed platform and actually finish it off. This includes the addition of a manually pivoting tailgate, complete with decals. There is a significant gap when you open the tailgate, which is troubling if you want to hold smaller items. To a degree separation is unpreventable because of the swing angle, but you could certainly add a layer of tile or half-beams to split the difference.

Before we wrap this one up, we have to make the logs and chainsaw that go along with this set. From the side, the chainsaw looks okay, despite the uninspired decal saying “CHAINSAW” on the side. From any other perspective though, it’s not great. The center is completely empty and the handle is too long. Nice try, but a bit rough. At least the chain spins. And the logs are… well… logs. Glad to have them though!

That concluded the build portion, so now let’s take a look at the finished product…

The completed model

This one is a real beauty if you ask me. There are so many features, techniques, and details packed into this ATV, it will make any Technic fan giddy. The suspension is about as good as it can get on a model of this size, and it just looks slick. Even though it doesn’t appear to have any particularly new elements, you don’t miss them at all.

The completed utility bed can hold quite a bit of stuff, whether that be logs, rocks, or whatever you’d want to haul. I like the clearance, and I also like that you can fit the saw or other tools behind the seat rather than in the bed if you wanted. It’d be easy to add a tow hitch and other accessories too, even though it’s quite packed with features already.

The winch is fairly strong. At least as strong as your fingers are. I tried this out by pulling another vehicle and it had no problems, though the mechanism is fairly slow (expected). The GIF below is sped up X3.

Conclusions and recommendations

There you have it! Another Technic model in the books – and an awesome one at that! I’m sure you can tell from the the tone of this article that I have almost nothing bad to say about the ATV. I truly love it, which is exactly the opposite of my last review, the new McLaren Formula 1 Race Car. This thing packs more punch is any single one of its play features than the entire McLaren. The set is technically a little over half the size in terms of piece count, but it feels like it’s so much bigger and more interesting. Also, it’s less than half the price. Comparisons aside, though, the model was a blast to build with all of its neat engineering, and just as much fun to play with! I would highly recommend this vehicle to any LEGO Technic fan.

The LEGO Technic 42139 All-Terrain Vehicle just became available today, March 1st, and retails for US $79.99 | CAN $99.99 | UK £64.99.

The LEGO Group provided The Brothers Brick with an early copy of this set for review. Providing TBB with products for review guarantees neither coverage nor positive reviews.

1 comment on “LEGO Technic 42139 All Terrain Vehicle – A vehicle that really does have it all [Review]

  1. Pierre CHARLES

    The model is indeed interesting but there’s a big no-no for me: there’s no model B.

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