I acquired the Tri-Wheeled Tyrax unknowingly from a large garage sale when I was about 5 years old. My mom found all these Blacktron: Future Generation pieces for some cheap price (to this day, I do not know what it was, but knowing my mom and the financial constraints my family existed under at the time, the entire lot of it had to be under $10 or no dice). Of course, being only 5 years old and totally ignorant of any Lego themes outside of Town at the time, the pieces ended being used for a myriad of my own fantastical creations. Even after I became aware of the fact that I had several complete Blacktron sets on my hands (including the awesome Aerial Intruder), I had no idea how to correctly assemble them all, since I did not discover Brickshelf and their instruction scans until 2001.

When I did obtain instructions via floppy (no USBs for me back in at the start of the millennium), one of them was for the Tri-Wheeled Tyrax. Because it was such a small set, I had tried multiple times before to recreate using just images I had in catalogs. I got close, but was continually frustrated by the asymmetry of the vehicle.

As it turns out, it was a lot simpler than I thought. Still, I was fascinated by the "trike" design, which is what prompted me to construct the set in the first place. It was also the first set I owned with the mid-size space wheels, and I liked that. The slight forward inclination of the entire vehicle gave it a bit of a menacing profile, which I thought went hand-in-hand with a faction that had a very "dark" look to all the sets. Other pieces of interest to me were the antennas and the canopy strip that served as a windshield.

It was fun to play with, especially considering I had a veritable army of Blacktron sets to accompany it. Often I would team the Tyrax up with the Sub-Orbital Guardian and Grid Trekkor to form a sort of "perimeter" guard for an imaginary Blacktron HQ (note that I do not have the Alpha Centauri Outpost nor the original Message-Intercept Base). The Tyrax could also serve as a ground assault vehicle, with the front wheel used for battering and the antennas switched around to form "laser cannons." My imagination went wild with that set, so I enjoyed playing with it a lot.

Well...it's not THAT bad

Pros: well i like the design, i've always been a fan of trikes, and it looks like a nice exploration vechicle.

Cons: well.....erm..... there is no extra parts or acceseries (sorry for bad spelling) and it is really small

3.5/5

As small sets go, this is nice - if rather simplistic compared to eighties sets of the same size. The three-wheeled arrangement is a nice change, however, and it certainly looks capable of crushing enemies into the dirt. Not sure what a Tyrax is - in UK catalogues this set is called a Cruncher.

I'm going to completely re-review this set though I cannot say that I've entirely changed my opinion of it.
First simply allow me to admit, I do not like this set in the least; there are a number of details about it that particularly annoy me.
For one, let's start with aesthetics, the Tyrax is far from pretty, and to put it frankly is incredibly disproportionate. The wheels are massive, the axles are blocky and the cockpit is as streamlined as a brick wall in a wind tunnel. But that's just the looks of this mini-set.
At about $3-5 US you won't be getting much in the way of either parts or figures. The majority of the Tyrax is composed of larger parts (a pair of 1x6 bricks, a 2x8 brick, the obscenely large canopy windshield, 2 of the large whip antennae and 3 of the MEDIUM space wheels). The rest of the set's build is just the tape holding those parts together.
The worst part of it all is, I can't really say I'm exaggerating here at all, the set contains nothing of much notice in the way of parts so I'd have to strictly call this a collectors item.
Normally with small sets you can get a small pleasant surprise out of the level of detail worked into some of the models yet this one set seems to be missing the old space magic.
The back wheels (or at least the 2x2 axle bricks holding them) are only secured by the top 4 studs, which can in some situations cause instability. Additionally, given the size of the set, losing the antennae is not an impossibility (though not something I'd care too much about, that tends to be a problem with a lot of older sets).
The general design of the set is using a slanted chassis which is a rather uncommon technique (though can be seen in the blacktron buggies in 6981, Aerial Intruder, for a much better effect).
Lastly, the asymmetrical mounting of the front wheel is pretty basic and makes more of an attempt to look like it's SUPPOSED to be symmetrical (they even covered the open end with a support beam to look like the opposite side, though in reality it serves no purpose) yet makes no attempt at covering the open innards of the massive space wheel (which is mostly hollow).
Some quick pros and cons
Pros

• Blacktron Minifig complete with jetpack/airtanks
• Not too expensive, you're getting just about what you're paying for
• Slanted chassis
  

Cons

• Aesthetically challenged
• Largely composed of bulky/blocky parts
• Back wheels can pose a problem
• Awkward looking front wheel
  

So in summary, I guess I cannot say the set is truly an abomination, that would be a bit much, but it certainly is not anything worth going through a lot of trouble for. You're best bet may just be to piece this together out of spare parts, especially since nothing here is rare, uncommon or even hard to find. Normally when rating a smaller set I tend to measure something on the level of detail obtained with such a small part count while balancing with being a sturdy and "fun" model. Using these criteria the Tyrax fails on at least 2 of those levels in that the back wheels aren't entirely stable (as well as a few other points of weakness) and detail is rather lacking. As for calling this set "fun" I won't deny that you could have a lot of fun playing with it, but in that sense you could do the same with any other model with wheels. In short, having an odd and unique design doesn't quite save this set from its obvious flaws.

In the tradition of agreeing with people about stuff that annoys you, I also think the Tyrax was nothing special, and certainly could have been better. The wheels are too big, if there were suspension and the minifig sat lower then it'd be better...but there isn't and he doesn't, so too bad. I'd really recommend this set only to complete your BT2 collection, and I guess that's the purpose my Tyrax serves. At least you get a figure!