Durability is clearly our reason for being. At NNormal, we firmly believe that the longer we use our sports equipment, the less impact it has on the environment. The longer the life, the lower the consumption and emissions. For this reason, we conducted a study to determine how many kilometres our footwear lasts and to prove that durability is essential to reducing our footprint.
Durability test: Kjerag
We’ve conducted a study based on a sample of 511 runners of all levels from around the world. Here’s what we’ve found: your Kjerag should last 1,350 km before it’s completely worn out or before its lifecycle is over.
To reach this conclusion, runners provided us with data regarding their weight, the kilometres they ran with their Kjerag shoes, the terrain they used them on, and the level of wear on their shoes, which was measured using our durability scale:
Thanks to this scale, we were able to link the wear of each person's shoes to the kilometres covered and, consequently, predict the average lifespan of Kjerag shoes.
· Shoe looks & feels as new
· Light cuts visible on the midsole
· Slight toe delamination
· Performance level of midsole still feels as new
· Upper & Midsole show usage marks
· Lugs starting to wear off but still functional
· No big damages to performance of midsole & upper
· Heavy wrinkling & tears in the midsole
· Many abrasion marks visible
· Shape of the shoe starting to deform
· Performance feeling minimized
· Thoughts of buying a 2nd pair
· No more cushioning feel
· Loss of midsole thickness & give
· No more grip due to worn off lugs
· Abrasion holes or cuts in the midsole
Distribution of the kilometers predicting the end of life of Kjerag.
X Kilometers; Y % Population
Distribution of the 511 runners across the durability scale.
X Kilometers; Y % Durability Scale (5 = End of life)
A new approach to measuring environmental impact
What’s the point of calculating the emissions generated by manufacturing a pair of shoes without knowing how many kilometres the shoes will last?
At NNormal, we believe that durability should be included in the equation when calculating the environmental impact of sports equipment. That’s why we want to promote this methodology.
During the past season, we calculated that the emissions from our Kjerag and Tomir shoes were 7.5 kg CO2e per pair. Considering the average of 1,350 kilometres that our consumers run with their Kjerags, we have significant data that these shoes generate only 5.5 kg of CO2 per 1,000 kilometres.
Kjerag 5.5 kg CO2 / 1,000 km
How long do your shoes have lasted?
“Thinking about the carbon footprint of a shoe per kilometre, rather than just the total carbon cost, makes sense. We look at how carbon builds up in the shoe over time and use, not just at the moment of its manufacture. This helps us determine which shoes are better for the planet, taking into account their durability and longevity. This can also motivate companies to design shoes that are better for our planet in the long term.”
Brianna Rita Pagán
Deputy Manager at NASA Goddard Earth Sciences Center Data and Information
What should you do if your Kjerags wear out before 1,350 km?
If the sole wears out before that, you can resole your shoe with the Vibram Resoling Program.
Discover the program
If your shoes suffer any minor wear and tear, use your nearest cobbler to repair them.
When your shoe is completely worn out, bring it back so we can give it a second life.
Send you shoes
Foundation of durability
Developed with Matryx® Jacquard technology, the upper of our Kjerag shoe is four times more resistant than polyester, as it is made of polyamide and Kevlar® threads. Our study also concluded that the EExpure midsole is twice as durable as standard EVA.
We are currently working on a study that will test our iconic Tomir shoe. We want to find out how many kilometres our consumers can use them for on average. Due to this and our commitment to the planet, we will continue to research and place durability at the forefront.
More about Tomir