Distance learning
Durability, an outsole to provide grip on a wide variety of terrain types, a split in the carbon plate and the insight and expertise of ultrarunner Tommy Rivs combine to make a new shoe from Craft a product of interest for long-distance runners.
Swedish sportswear brand Craft has launched a new running shoe, the CTM Ultra Carbon, which it describes as “ultra- innovative”. Its durability and grip on a wide variety of surfaces mean the shoe is destined to break new ground and set new personal records across the world, according to the brand.
Explaining this claim, the brand’s product and marketing director, Daniel Högling, says Craft spent years in the laboratory obsessing (his choice of word) over aspects such as energy-return and heel-drop. In the end, this work led to the durability and versatility the company was looking for in a shoe that he insists will help runners gain vital seconds, perhaps even minutes over longer distances. “If you are competing at extreme distances,” Mr Högling says, “this is your shoe."
Lug love
A three-piece, lugged traction rubber outsole, the Ultra Trac, contributes to this. The different shapes and the configuration of the lugs help with landing and with toe-off traction, and provide grip on varied surfaces. This outsole is designed to be lightweight, flexible and to maintain high levels of durability.
The construction of the shoe also combines a proprietary, lightweight ethylene-vinyl acetate- based material called Vault Foam in the midsole with a carbon plate for energy-return. The carbon plate is also a proprietary component, which the Swedish company has called the Ultra Carbon Plate.
One point the brand makes about this is that the carbon fibre in the plate is carefully sourced from specialist suppliers and that its thinness makes it work “almost like a trampoline” in terms of energy-return. “It’s crucial how you put the fibres together to get the exact stiffness, torsion, proportions, flex-points and weight you are looking for,” Daniel Högling says. “We tested several versions during the development process."
Split vote
There is a split in the plate, which allows a runner’s big toe to press on the medial side while the other toes press on the lateral side. According to Craft, the benefit of this is that it creates torsion and, as a result, provides added rebound. The brand says it wanted “an aggressive shape” for the carbon plate. This was one of the areas in which it benefited from working on this design with well-known trail runner, ultramarathoner and physical therapist Tommy Rivers Puzey. This happened before the athlete, known in the running community as Tommy Rivs, became ill with cancer in July 2020. “At first Tommy felt the carbon plate was too stiff, torsion-wise, during the field tests,” Mr Högling continues.
Bearing in mind that ultra-distance races often involve quick turns on difficult terrain, they came up with the split-toe design, which makes the torsion less stiff in the forefoot but represents no compromise on the forward drive that a carbon plate can give.
Tommy Rivs began his dialogue with Craft about shoes several years ago and began working formally with the Swedish brand in 2019. “We had the idea of making the most versatile carbon-plate running shoe on the planet,” Mr Högling says, “and to take it to an extreme fastest-known-time (FKT) challenge, but those plans changed due to Tommy’s health conditions. He contributed a massive amount of insight to the research and development process and performed a number of field-tests on prototypes. He is still in direct dialogue with our research and development team. He is a fighter."
Whole system
Mr Högling explains that the considerations developers need to bear in mind when working on shoes for ultra-distance running differ only slightly from the requirements for standard-performance running shoes. “The sole profile, the foam technology, the weight, the toe-off geometrics, the last, the upper and, in this specific case, also the carbon plate need to come together as one piece,” he says. “They all need to work as a system together. For ultra-distances, what we found was the midsole profile and geometrics can help the runner a lot, if designed in an optimal way."
Combining the carbon plate profile, the rocker shape and various other details have led, Craft believes, to a design that can help runners save energy; their muscles work more efficiently during the run, the product director says. As mentioned above, durability, because the distances are longer, and grip that adapts to various types of terrain were other points of focus.
Shortly before he became seriously ill last summer, ultrarunner Tommy Rivers Puzey (Tommy Rivs) lent his expertise during the development of the running shoe.
All credits: Craft
