This Is Why RC Tires Balloon (And How to Prevent It)

Source: Robert Silvana Meikle

If you have a powerful RC car, the chances are you will experience what is known as tire ballooning.

Besides looking like something that should be physically impossible and, well, very entertaining, tire ballooning is something that you want to avoid.

Why RC Tires Balloon? RC tires balloon because of the centrifugal force they are subjected to when spun at high speeds. RC tires are made of relatively soft rubber that is not capable of counteracting the process of ballooning. The centrifugal force will pull the rubber RC tire away from the rim and cause it to expand or balloon. 

A lot of people joke that tire ballooning is a great way to cut your pizza. Unfortunately, I don’t think the tire will be good even for that.

Below I will get into more detail about tire ballooning, what you need to know about it, its dangers, and, more importantly, how to prevent it from occurring.

Wondering how to make your tires softer? See this post: How to Make RC Tires Softer in 4 Steps

Why Do RC Tires Balloon?

To fully understand why ballooning happens, we need to explore what tire ballooning is.

Check out this short video below. This an excellent demonstration of what ballooning looks like. Of course, it does not have to be as aggressive as in this case.

This is a very nice demonstration of what happens to the tire when it balloons. As you can see, the tire expands dramatically with the increase in the RPM.

But is it normal for RC tires to balloon?

If I have to be more critical, I must say that ballooning usually happens to almost all RC tires if rotated at high enough speeds. It is all about physics. And it is a natural process. As the RPM increases, so does the centrifugal force.

RC tires, usually, do not have any cords in them that will hold them in shape. As a result, the more centrifugal force they are subjected to, the more they will deform.

This brings us to the next questions that many of the beginner racers may have. Namely, is ballooning bad for the RC tires?

Is Ballooning Bad for the RC Tires?

Some of you may be wondering if tire ballooning is bad or dangerous. But there are a few things we need to go over first.

Oftentimes racers may consider ballooning the necessary evil if they want to achieve higher top speeds.

You see, as the tire expands vertically, it has a wider outer circumference. All things being equal, this should technically lead to a faster top speed, right? Well, not necessarily. Here’s the thing.

Related post: RC Car Not Turning? Here’s What to do

When the tire expands—in this rather unnatural fashion—although the diameter of the tire increases, the surface that actually touches the ground decreases.

The increased diameter should technically increase the top speed, but the reduced contact with the ground will significantly decrease the control, manoeuvrability, and traction of your RC car.

As the ballooning becomes more severe, this will affect the steering and control of the RC car. Turning will be harder, and the RC car will be difficult to control even at straight and flat sections of the track. The RC car will move in zigzags, and it will be extremely unpredictable. This often will lead to uncontrolled turns and sudden movements, which will end up in the car flipping and crashing.

On paper, an RC car with ballooned tires should be able to reach higher top speed, but due to the significantly reduced control and stability, high speeds will be very difficult to achieve.

Excessive amounts of ballooning will also generate high amounts of vibrations, which can significantly reduce the life expectancy of all parts of the RC car.

Excessive amounts of ballooning may also cause the tire to come off the rims. This may happen even if the tires have been glued. As a result, you may damage or completely destroy the tire and the RC car.

Overall, RC tire ballooning is dangerous and thus should be minimized or ideally completely eliminated. It can lead to irreparable damage to both the tires and the RC vehicle.

How Do I Stop My RC Tires From Ballooning?

The good news is that RC tire ballooning is preventable, and the process, although requiring some fine touch and good amounts of focus, is, overall, very easy and straightforward.

1. Turn the RC Tires Inside Out

First, you need to take off the tires and turn them inside out.

This may be a little tricky, especially if the tires are new and still a little stiff, but a little elbow grease should do the job.

2. Clean the RC Tires

Now that your tires are inside out, go ahead and thoroughly clean them.

You can use different products to clean the tires. For example:

  • Naphtha.
  • Denatured alcohol or rubbing alcohol.
  • Or another cleaning solution.

You want to clean each tire very thoroughly and cover every spot of it. Clean the center and around the tire beads as well. They have to be squeaky clean.

Related post: RC Tires Cracking: Everything You Need To Know

3. Tape the RC Tires

Proceed and put two layers of gorilla tape on the tire. Make sure to do that slowly and in a controlled fashion. You do not want to rush through this process as the tape must be put the right way.

Gorilla tape has a very powerful adhesive on it, and once you put it on the tire, it will stay there. Exercise extra caution as you may have only one chance to do it.

All tires should be taped in the same way, with the same tape, and should have the same number of layers.

Make sure to have the ending edge of the gorilla tape fall at the same spot where the leading edge is. This will ensure that the tire is taped evenly. That way, the pressure will be evenly distributed across the whole section of the tire, and the tire will remain well balanced. Make sure that the tape is well-centred as this may easily disbalance the tire.

Give the tape a few minutes to settle in and cling to the tire nicely.

4. Turn the Tires the Right Side In

Now that the tape has nicely clung to the tire, it is time to turn it the right side in. 

Do that as gently as you can.

Once the tire is turned the right way in, use your thumbs and walk through the inside of the tire pushing and straightening up the tape and any folds that there may have just appeared. 

5. Clean the Bead

The next step is to make sure the bead is properly cleaned. This preparatory step is necessary if you will be gluing the tires later on.

This step should be done even on brand new tires because they may still have some residual oils or compounds left on the bead. Make sure to clean the rims as well.

6. Prepare and Insert the Foam

Now is the time to squeeze in the foam inside each tire. But first, you need to do some preliminary preparations. These may or may not apply to your situation, but it is essential to be informed of them.

Here’s the thing.

Some people like to cut the inside edge of the foam so that they will have an easier time glueing the tires later on. Usually, this is done by removing up to 1/4 of the edge at a 45-degree angle. The easiest way to do it is by using a razor blade or a paper-knife.

The outside edge is usually not cut, but some people like to trim it as well (again at a 45-degree angle). Leaving the outer edge as-is will usually fill-up the tire nicely, but it can make the tire a little stiffer.

A trimmed outer edge will usually give the tire a more rounded shape, which may give your RC car a little more predictability on the track, but it loses a little traction. It also makes the foam fit in the tire a little better. 

It also depends on which tires you put the foam in. Frequently full foam is used in the rear tires, and full or trimmed foam is placed in the front tires.

When it comes to cutting foam, people nowadays do not cut the foam more than that. See, a few decades ago, foams were not what they are today, and, for example, many RC car owners would cut the foam into a star. This is not done anymore as foams today are of higher quality.

Now, when the foam is ready, it is time to insert it into the tire.

Squeeze the foam and fold it over. Insert the side of the foam where the single fold is located first.

When the foam is inside the tire using your fingers and thumbs massage and spread the foam evenly throughout the tire, the foam should be well-centered, and there should be no folds whatsoever.

7. Put the Tire on the Wheel

Mount the tire on the wheel.

Roll the tires around if needed in order to align the beads. Take your time and check the outer edges. Make sure that the beads are set properly. Double and triple check if needed because you want to be 100% sure everything is placed correctly, and no parts of the beads are showing.

8. Glue the Tire

Now that the beads are nicely sitting in place, it is time to glue the tire.

Some people have found it useful to wrap the outer edges of the tire with some electrical tape.

Using the electrical tape to provide a little pressure on the tire, you can make sure that the beads are under equal pressure and will stay in place while you are glueing them.

Now, this is the point of no return, so to speak.

Use CA glue to and gently apply it around the beads. Let the glue flow freely around and into the bead. 

Do not pull or put any pressure on the bead—this will allow the glue to get in deeper, but you may easily end up disbalancing the tire and misseating the bead.

However, if you have used the electrical tape trick I have mentioned above, you will be able to get away with opening the beads a little and applying the CA glue a little deeper into the beads.

Start with gluing the inside of the tire—this way, you can experiment and practice how much glue you need to apply and how to spread it.

Let the CA glue dry thoroughly—although it may say on the bottle to leave it for 1 to 3 seconds give it at least 15 to 30 minutes to make sure that it has fully dried.

Then when the glue has dried fully, proceed and glue the front part of the tire.

How Do I Stop Glued RC Tires From Ballooning?

Now, if you have glued tires that are ballooning, things can get a little trickier because, well, the tires are glued, and you have no way of accessing the inside of the tire to tape it.

Related post: Can You Reglue RC Tires?

If you have to deal with glued RC tires that balloon you have three options, (1) unglue the tires and follow the above-mentioned steps to tape the tires; or (2) you can use braided fishing line to tie around the tires and glue the knots; or, (3) alternatively, you can use those big hydraulic o-rings and glue them on to the tires.

You should use a heavier weight braided line at least 50 to 80 lbs or so. Wrap the fishing line 2 to 4 times around the tires and glue the knots. You want to keep the line between the lugs as this will prevent wearing it down. Do that for the center and the two sides of the tire.

The O-rings method is also good but a little trickier, and it may be more difficult to find o-rings that are a good fit and will be able to fall in-between the lugs.

Do You Have to Tape the Foam?

Taping the foam but not the tire will not prevent RC tire ballooning.

You need to tape the tire and not the foam. This is a mistake that some beginners do, which can do more harm than good. If both the foam and the tire are taped, this will reduce the traction between the tire and the foam. As a result, the tire may start to slide on the foam.

When that happens, the control of the car may be affected. It will feel as if you are driving on ice, so to speak.

The foam does not expand in the same manner the rubber tire does, so there really is no need to tape the foam as well.

Does Duct Tape Prevent RC Tire Ballooning?

The type of tape you will use for taping the RC tires is more important than it may seem. The tire will be subjected to high amounts of outwards pressure. The tape is placed there, on the inside of the tire, to prevent and negate that pressure, which will otherwise cause the tire to expand.

So, in other words, the tape should be able to withstand that pressure. The adhesive should be able to cling to the tire and not let go, and the tape itself should be strong enough not to rip apart.

So does regular duct tape prevent RC tire ballooning? Regular duct tape is not strong enough to prevent RC tire ballooning. Although it will do well at slow speeds once you push your RC car to higher speeds, there is a very high chance the duct tape will rip apart and allow the tire to balloon.

Use tape that has been proven to work. Using the wrong tape is not a fun experience and can be more dangerous than expected.

When the duct tape comes off, it will not do it uniformly—coming off from the whole tire—but it will do it only in one spot. The result of this is that this spot will balloon at a very fast rate, while the rest of the tire will not be affected, which will most likely cause the tire to tear apart. This will destroy the tire and render it useless and may also seriously damage the RC car.

Paul Good

This awesome hobby has something for everyone, whether you like to build your RC from scratch and keep modifying till you've got it to just how you want it, to track racing. You might be out with a boat, or perfecting your skills with a plane. Are you taking some cool pics with your drone? I'm sure my site will help you on your journey.

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