Foam inserts are one of the most important factors which can influence the way your tires perform on the race track. Tires of RC cars do not use air pressure to maintain the shape and size of the tire and this is where foam inserts come into the picture.
How did they evolve into such an important part of your tires? Well, in the golden age of RC cars, tires were either foam, especially for on-road use, or hard rubber, for off-road. The former one didn’t need inserts, and the latter was so hard enough that they could handle the weight of the car without changing size and shape. As RC car design evolved, so did the tires. They eventually got soft enough to require some foam inserts.
Most racing tires nowadays come with no foams at all, so you racers can choose the best molded inner foam for your needs. Also, several others come with an open-cell foam insert, which you can use if you are not involved in racing. However, if you do race, you should research the best tire and insert combination for your RC car.
A foam insert can have places in the tires either high or low pressure. So, your car can react differently at different points on the tires. In order to shed some light on these foam inserts, we have to state that there are basically three types of foam inserts. There are regular foam inserts, square-cornered and flat-faced. The second type is called dual staged foam inserts. These are also square-cornered and flat-faced, but they usually have a harder band of foam on the outer edges and a softer band in the center. The third type is referred to as molded RC foam inserts. The face of the insert is molded like the inside of the RC tire. These molded inserts can be reused.
Choosing foam inserts for your tires can be a bit confusing, especially if the manufacturer will include foam inserts in your new RC car. But, as we said above, if you are into racing, you should choose your own foam inserts. You should be careful to check out their softness or hardness, their width or if they are dual-stage.
Let’s check out the importance of the inserts’ width. As a general rule, you should know that wider inserts are better than narrow ones. They should be at least as wide as the tire itself, but you can also use wider ones.
How do you choose between soft and hard inserts? Hard inserts will support the tie carcass better and the tire won’t lose shape when you’re racing. But remember that firm insert can also impair the RC car’s ability to absorb bumps. So, if you’re about to race on a bumpy track, you should choose a firmer foam insert. Don’t choose a very firm insert, because it can cause the vehicle to bump all over the place. This one is a bit tricky because soft foam inserts won’t help your car in handling corners. Dual-stage foam inserts are your best bet. The soft center will absorb all the bumps in the road and the firm edges give you great cornering ability.
Molded foam inserts have one important advantage: they are totally reusable. Also, they let your tire work to its full potential, because to do well with high and low-pressure areas in the tire. Another important tip regards the ratio between the foam’s inner diameter to the rim’s outer diameter. The foam inserts need to fit tightly over the rim! As you may have seen, Foam inserts require a lot of careful consideration, so take your time and analyze all the available models to find out the perfect one for your RC car.