For my other review of the summer 2021 LEGO Technic sets, I have the other larger set in the wave with the 4×4 Mercedes-Benz Zetros Trial Truck (42129). The set has 2,110 pieces and retails for $299.99. It is able to use the newer CONTROL+ system to remotely control it. The parts are packed into bags numbered to six as well as bags for the motors and hub. There is also a very large sticker sheet as well. Again, I’m not all too familiar with Technic so I probably will get some of the terminology wrong.
The first set of bags is for a majority of the chassis. In the middle of it, you get the main gear mechanism in the build which is the differential lock for allowing the wheels to rotate at different speeds. With a flip of a switch, you can lock them by forcing the wheels to rotate at the same speed. There are a couple of motors that allows you to do that.
The second set of bags is mostly for the rear axle. It attaches to the back of the truck by connecting to some springs that also act as the suspension.
Next up, you have the front axle assembly which also makes use of a motor for the steering. Like with the back, there are some springs for the front suspension as well.
Bag four is for the large truck cabin. The inside of it has room for three seats along with a steering wheel with a stickered Mercedes-Benz logo. The door assembly also has a couple of mirrors that are also stickers. In addition, there are a lot of detailing stickers that are all around the sides of the cabin area.
The next set of bags is dedicated to the front hood area of the Zetros. There isn’t that much going on here but the logo is a printed dish piece. It is attached to the chassis using a couple of Technic beams which allows it to flip forward to show the engine.
Finally on the last set of bags, we fill out the bed of the truck. The thing that stands out the most is the bright green sides to give it some contrast to the gray on the rest of the truck. Like with the side panels, there are a lot of stickers of fake sponsors. They are the same for both sides, just mirrored.
The only way to operate the truck is to use the CONTROL+ companion app. The controls are pretty straightforward and it gives good instructions on how to operate the Zetros. The app also gives you an augmented reality view of it. One of the more fun things to do is the challenge mode where there are a number of challenges to complete for achievements. It also keeps track of high scores so you can try to outdo them if you wish. You can check out Sariel’s video below for a visual representation of how the app works below.
Overall, I feel the LEGO Technic 4×4 Mercedes-Benz Zetros Trial Truck (42129) is an underwhelming set. The build itself wasn’t too interesting but you do get to learn about differentials by building it. There are areas of the truck where it is somewhat fragile like the hood and doors as they tend to open up be themselves if the truck is slanting forward.
Once you get the truck going, it is really slow so you won’t win any races against other remote-controlled Technic sets however it shines if you take it outdoors and you have it climbing different terrains. Considering the price of $299.99, you wouldn’t really want to get the parts dirty, especially in the motors, so that’s something to take into account.
The set is a total contrast to the Heavy-Duty Tow Truck (42128) which I’ve reviewed here. Although that set also had some unsightly stickers, the play features on it was top notch compared to the Zetros. Without the companion app, it just sits there as the wheels are connected to the motors and there’s really no other features there. If I was in a position to buy it for $299.99, I would suggest wait for a sale and even then it might still be too expensive for what you get.
Thank you to LEGO for sending in this set for me to review. The content above represents my own opinion and not the company. Review sets sent in does not guarantee a positive review.
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