Gum rubber is a material used in the outsole of Adidas shoes, and is it used in the vast majority of Adidas heritage sneakers; this line of products is currently named Adidas Originals. Gum rubber is renowned for it's flexibility.
Gum rubber is also referred to as 'natural gum rubber', 'India gum rubber', and 'pure gum rubber'. Gum rubber is referred to as 'India rubber' because it is formed from latex procured from the para rubber tree. Henry Wickham smuggled para rubber tree seeds from South America to India; creating an important industry of the British Empire. One of the properties of gum rubber is it's abrasion resistance; which makes it ideal for a shoe's outsole: the part of the shoe that touches the ground. Gum rubber has protective properties, it is resistant to: acids, organic salts, and alkalis. Gum rubber's protective ability is why it is picked as an outsole in work boots like CAT footwear. Gum rubber does not tear easily - like leather outsoles do - which makes it ideal as an outsole for the majority of sports, and sports that are played on hard and rough surfaces. Gum rubber is also waterproof, which again, makes it ideal for most sports and especially for outdoor sports. Modern Adidas sneakers tend to feature Adiwear rubber rather than standard gum rubber; Adiwear is a non-marking rubber that is ideal for indoor surfaces, and undergoes a process of vulcanisation that makes it more durable than gum rubber.