Easy Way to Figure Out the Wheelbase of Any Model Kit for an RC Chassis 📏

Ajouté : 2026-05-28

[00:00:00]Certain specific measurements, such as the wheelbase of a plastic model kit, is generally not listed anywhere on the box, nor stated in the product description. For the radiocrolled model builder, this can be a bit annoying, as it can make it a lot more difficult to know whether or not a specific body will fit your chassis. Fortunately, there's a very easy method to determine the wheelbase of just about any model kit without even having to open it up.

[00:00:22]Hopefully, today's video will be helpful for all of you builders out there when it comes to determining what bodies will fit certain chassis.

[00:00:32]Hello everyone and welcome. I've got a quick video for you all today that I hope will be helpful. While the information might not exactly be news to some of the more experienced hobbyists in my audience, and I think I have covered this topic at least a few times in some prior build videos that I've posted here on the channel, I hope this video proves to be a great source of information for those interested in utilizing highly detailed plastic model kits for one of their smaller scale RC projects. As you're probably already well aware, plastic model kits, which are commonly found in either 124th or 125th scale, can be found replicating all kinds of different vehicles, which naturally come in all different shapes and sizes, just like their real world counterparts. In the more conventional world of 110th scale radiocrolled vehicles, bodies are generally matched to a specific RC platform, such as the SCX10 or Tamilia TO2, for example.

[00:01:22]Sometimes it's more like building Legos where everything is just sort of compatible and fits the way that you would expect, whether it be wheels, bodies, or electronics. However, as we start to get more and more lifelike with how closely we want to replicate the real thing, and as we start going to smaller scales, utilizing plastic model kits not specifically designed for certain RC platforms, things can get a bit more difficult. Measurements like the width and wheelbase are not standardized in the world of plastic model kits. They are instead generally extremely accurate replicas of the full-size vehicles, taking real world dimensions into account during their design. This variety of different sizes can certainly be a bit of a pain when it comes to choosing a model kit to fit a specific chassis. However, with this being the case, we can actually determine the dimensions of the body included quite easily. I'll use this Monogram 85 Camaro Z28 kit as an example, a recent swap meet score that I'm sure you'll be seeing in some future tutorial videos here on the channel.

[00:02:18]still factory sealed, but I can pretty much guarantee what the wheelbase of this body will be, even without opening it up. The only dimension that I see that's provided on the box is the total length of the model, which is 8 and 1/8 in or a little over 20 cm. This is something, but the bumperto-bumper total length isn't really all that relevant when deciding if it will fit a specific RC chassis. The wheelbase, which is the distance between the center of the front axle and the center of the rear axle, is what we're after. Since I do have the kit here, I obviously could just open it up and measure this distance. But putting myself in the position of somebody browsing model kits online or in a hobby store, I can do this entirely without having to access the body itself. I know the make, model, and year of the car, as well as the scale that it's in, which in this case is 124th.

[00:03:05]Make sure you do know whether the vehicle is in 124th or 125th scale, as the exact scale it's in will make a difference here. Not necessarily a huge difference, but we want to try and be as accurate as possible. But all I have to do is figure out what the wheelbase of the real car would be, which is information that should be readily available for basically any production vehicle. In this case, it looks like the real car would have a wheelbase of 101 in or 2565 mm. With this being a 124 scale model, all I have to do is divide this number by 24, which gives us 106.9 mm, which I'll just call 107 to keep things simple. I just so happen to have another one of these bodies sitting on top of a 107mm FFR SC1 chassis. And there you go.

[00:03:47]As you can see, this body will accommodate a wheelbase of right around 107 mm. This should apply to basically any measurement on the body, such as the total width. So, we can get an idea of how wide the body will be relative to the chassis as well. Generally, we wouldn't want to be in a situation where the body is extended far beyond the outer edges of each tire, nor have the tires sticking out well beyond the fenders. This is why we have so many differentiz parts for our chassis and drivetrain components over on our Patreon. This allows us to 3D print chassis and parts to be used with a variety of different model kits. With your more conventional storebought RC platforms, they might not allow for a huge amount of adjustability, if any at all, but this will vary from one platform to another. There may also be aftermarket parts available, such as adjustable fourlinks, that can help you dial in the exact wheelbase to fit an aftermarket body, such as one included in a plastic model kit. Here's another showcase of how this method of looking up real world dimensions can be useful.

[00:04:45]Let's go in the other direction and try to find a nice model kit that could be compatible with the popular Axial SCX30.

[00:04:52]It's possible to adjust the wheelbase and even the width to a certain degree on this platform by utilizing different suspension lengths and different wheel offsets. But according to the specs, out of the box, it has a 99 mm wheelbase and a 70 mm width. 99 multiplied by 25 is 2,475 and 99 multiplied by 24 is 2,376.

[00:05:15]So, let's see if there's any real world 4x4 vehicles that have a wheelbase of around 2,400 mm. While there's certainly no shortage of things that can be criticized when it comes to the proliferation of artificial intelligence, it can be a great tool for research, such as the case here. Just make sure that you're always checking the results for accuracy, as especially with more niche topics such as this, it's definitely far from infallible. But right off the bat, we're getting some pretty iconic vehicles here. Land Cruisers and Land Rovers, as well as first gen Broncos and CJ7 Jeeps. All of these vehicles you should be able to find replicated in plastic model form.

[00:05:52]For example, I know that Rell recently reissued their 1977 Jeep CJ7 which are in 124th scale. If we divide the real world wheelbase of 2375 mm by 24, we get 99 mm. If we divide the real world width, which would be around 1,650 mm, we get around 69 mm. Doing the math, it sure seems like this Rell 77 Jeep CJ7 replica would be a near-perfect fit for the Axial SCX30 chassis. No width or wheelbase adjustments being needed. Now, I have neither a SCX30 nor that specific model kit. However, after doing a quick search, it looks like somebody on the popular SCX30 mods, upgrades, and fun Facebook group has used this specific kit with a greatl looking result. All credit here, of course, goes to Tom, but just as we calculated, the wheel basease and width looks correct for the body. Now, obviously, I'm sure a fair bit of hacking was required in order to make it all work, but that's certainly to be expected. Also, the wheels and tires that come on the SCX30 are going to be a lot larger than what would have come from the factory on a real Jeep. So, as long as you're okay with more of a purpose-built off-road crawler look, it should all work well. Sure, we have to do a little bit of math here, but this is why I really like that these plastic model kits are generally true mathematical representations of the real thing. Unfortunately, accurate scaling or dimensional accuracy in the world of more conventional tent scale RC vehicles is generally not nearly as sacred. The stated scale in the world of RC is often really more about marketing than it is a true mathematically accurate representation. But not only do these models look correct when parked next to each other, which is more than can be said for many popular 110th scale RC vehicles, but we can actually figure out the numbers and get a good idea of what will fit and what won't, even without having the body on hand to measure. Like I said, even without owning an SCX30 or that Jeep CJ7 model kit, I could have told you with pretty good certainty that that particular body will fit on top of that chassis. And fortunately, we have some other great hobbyists out there posting their projects to prove that it will in fact work and look great. Now, is this an entirely foolproof method?

[00:08:01]Not necessarily. We are assuming here that the model makers accurately base their design on the real world vehicle dimensions and have stated the correct scale on the box. From my experience, this has always been the case, but there may be some exceptions out there. Also, it's important to be aware that some vehicles, especially things like pickup trucks, would have been offered from the factory in different wheelbases. For example, a long bed versus short bed.

[00:08:26]When you're getting these real world dimensions, make sure that you're getting the correct ones for the specific variation of that vehicle represented in the model kit. But anyways, that's just a little tip for all of you RC model builders out there, or those looking to utilize a body from a plastic model kit on your more conventional RC platform. I hope this trick proves to be helpful. If you did, clicking that like button and sharing it with others you think may enjoy it as well is always appreciated. That's all I've got for today's video, though. As always, thank you all very much for watching. And of course, a huge thank you to all of our channel members and Patreon supporters who help to make these videos possible. I'm currently chipping away at some larger projects, but hopefully some of those builds will be finding their way onto the channel before too long. Until then though, best of luck with your projects and be sure to stay tuned to see what's next.