The Basics of EVA
Vs. Rubber Soles
Rubber is a natural material, and the most commonly known form is latex rubber. It is derived from the sap of the rubber tree plant. Both are used as soles in athletic under garments.
If you’re in the market for running shoes, you’ll likely come across both EVA and rubber soles. So, what’s the purpose of each?
EVA soles are typically used for the mid-sole as they are capable of providing better shock absorption. The foam compresses with usage, which makes it absorb impact and soften the blow.
Rubber soles, on the other hand, serve the purpose of traction. Rubber on a shoe sole gives you a firm grip and traction on a slippery surface. Rubber soles are also ideal for construction jobs as they provide better insulation from electricity.
The rubber sole is also considered better for protecting your toes from stubbing when you have a tendency to walk on your toes as it offers greater protection.
The Basics of Rubber
You may not have realized it, but most of the shoes that you currently own have one of two types of soles.
You see, most shoes are made with either EVA or rubber soles.
But what’s the difference between the two? And which is better for your running needs?
Let’s find out!
EVA or Epoxy ethylene vinyl acetate is a polymer plastic foam. It is hard but, still flexible and, most importantly, light. The higher degree of flexibility of EVA is actually one of the main benefits of this type of sole. This allows the shoe to provide a more natural feel and more comfort for runners. EVA sole is the most popular choice for Cross Fit shoes and other training shoes. EVA also provides great traction when it comes to running. This is great news for runners who are looking for a solid grip when running on different terrains. On the other hand, EVA sole doesn’t help with durability. Therefore, it’s a less popular choice for long distance runners who typically want a durable footwear.
Vs EVA. Which Is Less Polluting?
EVA sole or rubber sole has been a major component of running shoes for over three decades now. The reason is simple: It can be molded into any shape, which makes it the most symbolic element in the process of creating a new running shoe.
EVA and rubber are both very useful and versatile materials, but they do have their differences.
EVA, or Ethylene-vinyl acetate, is a synthetic material that is commonly used in shoe manufacturing and is chemically similar to the polyvinyl acetate used to make typical grocery store plastic wrap. This material is usually made from ethylene, vinyl acetate, and a pair of plasticizers such as diethyl phthalate and di-n-butyl phthalate.
Rubber is a natural material that acts as a shock absorber when worn inside the shoe. It conforms to the shape of the wearer’s foot over time and makes for a very comfortable fit. Synthetic rubber, like EVA, is very versatile and can be molded into a variety of forms.
Rubber is formed from the sap of a rubber plant. The sap is harvested and then processed through a manufacturing process to create the shoe material. It’s then made into soles and sold to companies like Adidas and Nike.
Or Ethylene Vinyl Acetate: Which is the Best Sole?
There are two things that make up the upper part of your running shoes: The upper and the outsole. Let’s start with the upper first. This is typically made from two materials: Mesh and Textile.
Mesh: In case of mesh, the wires that are interwoven in the fabric hold the structure together. The material is breathable, allowing your feet to sweat and promote airflow during your run.
Textile: In case of textile, there are threads stretched across which create tension. The tightness of the threads creates the structure of the shoes. Textile offers a lot of support, but lacks breathability. It provides better cushioning and support than its mesh counterpart.
The sole is usually made from two materials: Rubber and EVA (Ethylene Vinyl Acetate).
Rubber: This material is hard and sturdy to provide better traction and durability.
EVA: As the name suggests, this material is made by joining Ethylene and Vinyl Acetate. This material is a soft, semi-elastic foam that provides cushioning and flexibility to running shoes.
EVA Sole vs Rubber Sole: Outsoles Matter
We all tend to use the same brand of shoes over and over again, so it feels like the rubber soles are practically part of the shoe. But did you know that most of the common running shoes have rubber outsoles made by two different methods? And these methods can actually make a material difference in durability and performance.
Rubber (Natural Rubber from Rubber Trees)
Rubber outsoles are made from natural rubber extracted from rubber trees. Trees are cut, heated, and heavily processed to create the material you find in your shoe. A rubber outsole with this method begins to deteriorate as soon as you wear it down. But it is usually readily available and inexpensive.
EVA (Ethylene-Propylene-Diene Copolymer)
EVA outsoles are made from a more modern process that began in the 50s. The raw material used for this method is derived from chemicals derived from petroleum. They are hard and durable with a particular trait that helps them resist abrasion and slipping. And unlike their rubber counterparts, EVA soles can be recycled and are more environmentally friendly. It might be slightly more expensive than rubber, but EVA has proven to be a better option for athletic shoes.
Which Is Better for Running?
EVA or Rubber?
EVA has been the go to sole material for running shoes for a while now. Its cause has been championed by companies such as Nike, Adidas, and Asics. But in recent times, there is increasing momentum to change the situation and incorporate more rubber as a sole material.
Earlier this year, competing brands ASICS and UnderArmour broke up a long standing alliance and ASICS adopted the change into their running shoes. ASICS stated that it was for two main reasons. The first one is that the rubber sole delivers better energy return which is perfect for running. That is especially relevant when going for off-road races. The second reason is that the rubber sole is more durable than EVA as it holds up better over time under intensive use.
Now, this may echo concerns in the EVA vs Rubber debate. Applying the durability argument to EVA vs Rubber would mean applying it to the midsole. And any runner who has dealt with the wear and tear under their feet knows that EVA midsoles wear out fast. But of course, this also depends on the amount of usage.
Will the addition of the rubber sole to running shoes make the difference in the EVA vs Rubber debate?
Choose Depending on Your Need
EVA and rubber soles are the two main categories of shoe outsoles and both have their specific benefits and uses.
EVA soles are known for their cushioning and shock absorbing properties and are usually equipped with a rubber part in the heel to provide traction. EVA also has a tendency to be lightweight, durable, and more shock absorbent than rubber.
Rubber soles are by and large more durable than EVA while being able to provide a bit more traction than EVA. Rubber outsoles are usually made of either natural or synthetic rubber.
They can come in variants with a harder or softer rubber layer to best suit the needs of the runner. They can also be made with reinforced heel parts or combination of hard and soft rubber to obtain better traction.
There is no real clear winner between EVA and rubber sole, as both have their own strengths and uses.
Ultimately, it is up to the runner to choose which type of sole is best suited for their running experience.