It’s time for another official LEGO set review here at The Lego Car Blog, and it’s a big one. Welcome to the Claas Xerion 5000 Trac VC.

This TLCB staff member has wanted to get his hands on LEGO’s 42054 Claas Xerion set ever since he first saw it. A large lime-green tractor now sits next to him as he types, so has it met expectations?…

42054 sits, a little surprisingly, in the middle of the current Technic range. A little while ago it would have probably been the Technic flagship, but so huge are the current models getting that the Claas is less than half the price of the Volvo L350F and Porsche 911 GT3 RS. However at almost 2,000 pieces 42054 actually features a few hundred more than the big Volvo.

Many of these are new too, with brand new (awesome) tyres, and a wealth of new bushes and pin connectors making their debut in this set. LEGO have employed a few interesting techniques in building with these, as some of these parts are used purely as a construction aid (think an unseen bracket on a car bodyshell that serves no purpose once the car is built, but allows a robot to align a laser or something during manufacturing), and all are coloured in a way that aims to assist with the build process (as opposed to the colour being chosen to best suit the finished model’s aesthetics).

If that makes you concerned about how authentic the Claas looks, don’t be. 42054 is one of the finest looking Technic sets ever produced, and it continues the trend of featuring almost Model Team levels of detailing, with Technic lift-arm holes concealed by smooth plates, lights, mirrors, and some very well chosen stickers.

The downside of the aforementioned colour choices is that black and dark grey parts can look almost identical in the instruction booklet, and when you first come across one of the new pieces you may spend ages looking for it amongst a sea of 2,000 bricks, scanning for black, when it is in fact nestling in a pile of grey. Not that this reviewer did that of course. He’s far too experienced to make that mistake.

Colours aside the instructions are clearly laid out, and feature some huge sub-assemblies. Which brings us neatly on to a new phenomenon that the Claas Xerion demonstrates wonderfully; Density of Engineering.

Yes, we have just made that phrase up, but 42054 features some of the most compressed and tightly-packed mechanics of any LEGO set. Ever.

It’s the first set where the design has genuinely amazed us in its complexity – it’s so far above our building ability that we could never hope to better it. Some of this engineering brilliance fulfils relatively simple tasks, for example when the motor isn’t in use the battery box is automatically switched off (a thoughtful piece of design), whilst other elements, such as the three-mode steering, are mind-bendingly fantastic.

So, the steering. Like the real Claas Xerion, 42054 can be steering by the front axle (as it would be in road use), all-wheel (for tighter turns) and crab (to avoid furrows). All three work perfectly, and – as always with LEGO sets – all three have an absolutely appalling lock. It’s good thing this set has all-wheel steering as you need it just to navigate household furniture.

42054 also includes a bit of a steering party piece though, as the cab can rotate through 180 degrees, rising subtly as it does so to clear the hood, to allow the driver to see the rear-mounted crane. This is the first function controlled by the Medium Motor, and it works beautifully.

A gearbox and a set of clutches split this single motor’s drive to allow it to a) power a number of functions and b) run continuously without stress. The power sent rearwards controls a slightly awkward-looking crane, allowing it to rotate and elevate courtesy of a linear actuator. Both functions are controlled via two easy to use (and easy to access) levers mounted at the very back of the set. The crane also includes a few mechanical functions too, with the boom extension, stabilising legs and grab all controlled by hand.

And this is where the Claas earns big points here at TLCB. Too often with the more recent Technic sets we’ve got the feeling that Power Functions electric components have been included at the expense of mechanical functionality. And sometimes even any functionality at all. Not so with 42054, where the use of the Medium Motor absolutely enhances the set, yet it would remain a magnificent Technic model even if a motor weren’t included. Aside form the brilliant three-mode mechanical steering, crane boom extension, grab and stabilisers, two more hand-powered linear actuators raise and lower both the crane at the rear and the counterweight at the front of the Claas. These are complicated mechanisms that probably didn’t need to be included, yet they have been, and we love 42054 for it.

LEGO’s 42054 Claas Xerion 5000 is – quite simply – a triumph. It looks fantastic, it works brilliantly, it’s challenging to build, it’s a delight to play with, and it’s quite possibly the most superbly engineered LEGO set yet. It’s also good value, with nearly 2,000 pieces for less than half the price of the current flagship sets. If you’re reading this and you don’t own 42054, buy it. Buy it now.

★★★★★