Threaded Aluminum Wheels, Pt I: What’s The Deal, Really?

No one can get into Thunderjets-or even later AFX slotties-and not sooner or later encounter one of the oddities of the hobbies’ past: AJ’s threaded aluminum wheels.

Over time I have acquired maybe 5 sets of these by buying old cars or, in some cases, old chassis, that had them fitted by a previous owner. At first, I admit, I was flummoxed.

OK, so sure, I can see why you might want aluminum instead of plastic wheels on your slotty: at a glance, the benefits seem obvious: better durability, truer running leading to better performance, and maybe-for those that cared-a more professional or “serious” look. OK, good start…

Over the years, I’ve seen a couple of different designs, chiefly that some have the splines set up in the middle of the axle while some others have shorter splines offset to one side, meaning that they can only be mounted one way in the chassis for the crown gear to seat correctly into them. I’ve also seen several variations on the wheels themselves; there are several different diameters, some have a deeper dish than others, and one particular design I like has a sort of 5-spoke center pattern which looks pretty cool.

Apparently there was also a press-on style of aluminum wheel, although I have never seen these; I also know there were a variety of different types of tires made by AJ’s, and from different materials, including natural rubber, German formula open-pore rubber, silicone, and foam tires. Each type catered to specific traction and performance needs.

OK, all good. And yet, right off the bat, I noticed something that made no sense to me…

Why are the axles not counter-threaded, so that when the car moves forward, the wheels on both sides tighten on the threads? This seems like it would have been the most basic no-brainer of this design, and yet, for some reason, the threads are not counter-rotational; both sides of the axles are threaded in the same direction, which means that one of the two rear wheels-usually the inside one, if you are racing counter clockwise-is by nature going to want to un-thread and spin off the axle as the car begins to move. The solution to this is the use of a jam nut, which threads onto the axle first before the wheel is fitted, creating a backstop affect to prevent this spin-off from happening. While this works, it seems like a strange solution to a problem that, to my mind, has a much more obvious solution! Even with the use of the jam nut, making the axle threads counter-rotational seems like an obvious move. And so, I ask my fellow slot racers: what am I missing here?

Perhaps there’s something my feeble mind just isn’t grasping, but when you take this lack of counter-rotational threads into account, the advantage of the aluminum wheels in racing seems to all but evaporate. Apparently, I’m not the only one who thinks so: the research that I’ve done has revealed that many racers have reported challenges with the installation and performance of AJ’s threaded axles and aluminum wheels, such as wobble due to potential misalignment during installation or manufacturing inconsistencies, and I myself have seen inconsistencies in the diameter of the axles, leading to loose fits for the nuts and the wheels. In such cases, some people used adhesives like super glue or retaining compounds like Loctite to secure wheels onto axles…all which makes you wonder, what’s the point? Given these problems, the stock plastic wheels seem far superior!

Maybe part of the appeal was simply being different and customizing your car, which is worth something even if there’s no performance advantage: this was the topic of one of this blog’s very first-ever posts, and one in which I explained that were it not for the customizability of the wheels and all the different cool designs from the likes of Vincent and Road Race Replicas, I may never have even gotten into this hobby! Considering that these products were introduced in the late 1970’s long before those two companies existed and before there was a large availability of customized plastic wheels, these AJ’s products might have been about the only game in town…and that makes the whole thing much more relatable to me! Seen in this context, it begins to make sense…

All this got me interested in the origins of these parts, so I did a little digging there as well: AJ’s operated under the parent company Twinn-K. In the early 1990s, the Winn family sold Twinn-K to an investment group, and by 1996, Twinn-K ceased operations, and its assets were liquidated to various slot car and RC manufacturers. Despite the company’s closure, AJ’s products remain in circulation among slot car enthusiasts. NOS items still show up on platforms like eBay, and some distributors, such as REH Distributing, have been known to stock AJ’s products. Collectors and racers continue to seek these components for their vintage appeal and performance characteristics.

Which brings us to today…

In a world where we do now have a large variety of plastic wheels to customize our slotties, the original AJ’s pieces from the past don’t seem to have much appeal; the few that I have are only on my Road Crew cars, and I keep them exclusively as nostalgia pieces, with virtually no thought given to performance. However, a while ago, I stumbled upon something online that interested me…

There is a vendor who has a business called “mikes-metals.com” who machines his own miniature aluminum slot car wheels. His work is very fine and the wheels look very good, although they are very expensive. A few months ago, I got curious enough to buy a single set of these, because I thought they just looked so good that it might be interesting to try them. The question, though, is: try them on what? One of the old original Aurora Road Crew chassis? That doesn’t sound too fun; I already know what that’s going to be like.

No, what I want to try is mounting a set of these on an Auto World Ultra G and seeing if, fitted correctly with brand new axles and nuts that have no history of misuse or abuse, what will the results be? Can these wheels and axles handle the tremendous speed and performance of the modern Ultra G format? Or will they just wind up spinning off the car and flying across the room, never to be seen again?

In preparation to answer this question, I acquired 2 sets of original, unopened NOS AJ’s axles and nuts, and then got another small group of nuts besides, figuring that with this many parts on hand, I’ll get enough quality fittings to work as well as possible!

The next question is, which car? Do I take one out of one of my racing fleets as an experiment, or would I prefer to buy a dedicated car for this purpose? And if so, which one?

Well, these burning questions will be answered in an upcoming “PART II” to this saga, when I fit these wheels and axles to a brand new, virginal AW (now Round 2!) Ultra G chassis and try putting it on the big TomyAFX track and seeing what we get!

I certainly don’t expect these wheels to ever replace what I’ve been using now for 5 years, but they may be an interesting variation to try just to see what happens! So stay tuned, fellow slot-heads, to see what results from this experiment, and don’t hesitate to contact me ahead of time if you think you know what the results will be!