Boot Tech: Soleplate Flexibility

Stiffness and flexibility is one of the more overlooked features on soccer boots, but they can make or break your boot comfort. How many people like it when their boots are as stiff as a rock? Not many. But what about when you wear boots so flexible they are practically a sock? Because there isn’t any responsiveness, you won’t have any spring in your stride when you push off.

I was inspired to write this when wearing one of the heritage boots I have. They are super flexible and when I ran with them, it seemed as if I wasn’t getting the same responsive push off that I seemed to have in other boots.

It is kind of a personal preference if you like your boots stiff or not. For example, the EnergyPulse technology on the Adidas Nitrocharge is designed for stiffness and adding a rebound as you push off the ground. Both Kevin and Bryan tested the Nitrocharge and had different reactions towards the EnergyPulse technology. Bryan found it to be extremely stiff and difficult to bend (Bryan’s Nitrocharge review).  He thought that it made for a difficult break in but it definitely gave a more responsive push off. According to Kevin, it felt rigid in his hands but in game you barely noticed them (Kevin’s Nitrocharge review). So when you order a pair of new boots, take into consideration your own preferences about stiffness and be informed about the boot you plan to buy.

Cinquestelle is one of those companies that is designed for comfort. Kevin tested the Colibri boot recently and found that they fit like a sock. Their boots can almost bend in half because they are designed to give the best possible touch on the ball. I guess that their philosophy is that if your foot can bend naturally then that will help your touch.

In the past, we have seen a carbon fiber sole plate from Nike – including on the Superfly. It was used to help drop weight but came with a number of disadvantages. Among them were durability issues, cost, and stiffness. They were extremely hard to break in and there would be significant pain caused by the stiffness after long periods of wear. As a result, Nike decided to revert to a glass fiber soleplate, which is now seen on the Mercurial Vapor IX. It is much improved compared to carbon fiber because it gives a barefoot feel while still being responsive during push off.

Another reason companies may make boots stiff is because of the “power” factor. On the Predator AdiPower, there was a power spine that was designed to minimize the energy lost when shooting. In other words, if you have a stiffer sole, you will hit the ball harder.

So, which soleplate is best?

This is where personal preference comes in again. All these soles were designed for different performance factors and you have to choose which is right for you. If you want the barefoot feel while still having some response, the Mercurial sole plate with glass fiber is the way to go. Or on the other hand, if you want the most natural feel you can have, than boots that are similar to the ones Cinquestelle have is the right way to go. I found that the only negative you have from a flexible sole is that it is less responsive. The stiffer soles can cause discomfort so the ones that aren’t in the extremes generally work for everyone.

In the end, boot stiffness isn’t that big of a factor. As long as you don’t have an extreme pair of stiff boots, you should be fine. Most soles will break in to a more natural feel that is usually the right range of flexibility for players. It does influence some parts of your game such as your touch, but the difference isn’t that noticeable.

Does boot stiffness make a difference?  Do you like your boots stiff or flexible?