International Dealer News IDN 149 June/July 2019 | Page 30

PRO GuIDe eXTRa Supersprox unveils new generation sprockets for KTM/Husqvarna Factory racing teams around the world are always looking for an edge. Supersprox has worked with many top teams over the past 60 years with constant development as new materials and manufacturing techniques become available and in response to the feedback they get from the race team managers they work with. Supersprox General Manager DJ Maughfling says: "In the past three years, engine performance has affected the durability of the commonly used technologies for the production of engine drive sprockets. The engineers here at Supersprox are responding with a different approach. "We have looked closely at all the products in our racing line, because in the near future historically suitable technologies will start to age out. Bikes are getting too powerful and racing partners are pushing to have their suppliers think outside the box. "With assistance from a technical institute, we have approached this problem scientifically and been able to analyse how weak points in the parts produced using established manufacturing techniques develop under the varying conditions and loads they are exposed to. The results were surprising. We realised 'closed die, hot forging' it would not be possible to solve the issues with existing metallurgy. A solution was proposed on the bases of a radical change in process. "So now we are embarking on a new technique - closed die, hot forging." Supersprox claims that this new process increases the sprocket tooth and core strength by more than 20%. Compared to billet machined parts, the process offers significant advantages. In a part made from billet, flow lines develop in the microstructure. The properties become anisotropic - that is to say that the physical properties of the material have a different value when loaded equally in different directions, meaning parts can fail under dynamic stress. "During forging, impurities align themselves along these flow lines. The microstructure flow lines in a forged part will be much finer than a billet microstructure and therefore stronger and more durable. Special details are being added into the forging to provide the highest strength at the teeth and spline area - something that can't be done with CNC-machining a billet". DJ says that a unique ultra-low carbon steel (purchased in Japan) has been used for the sprockets, helping to provide a very stable condition in the base metal. Although the sprocket doesn't have holes 'microstructure flow lines' drilled, DJ says it is actually lighter than the OEM sprocket because of the surface indentations. The aluminium core in this sprocket is a technical feature, allowing the sprocket to retain a critical thickness in an area where steel is not required. Currently available for KTM and Husqvarna models, DJ says "we will test market reaction and understanding, listen to feedback, and if the performance and response to these new sprockets is as positive as we expect it to be, then we will start to expand use of the new techniques elsewhere in our range." Supersprox are well known as the inventors of the patented hybrid sprocket, combining steel teeth with an aluminium core. In 2018/2019, Supersprox gained further five additional world titles, including the World Endurance Cup and the Dakar Rally, both using the original design of the Supersprox-stealth sprocket. Supersprox says it is one of the first sprocket manufacturers to use closed die, hot forging Forged blank Billet blank Forged blank, showing a finer grain structure when compared to a billet machined part. 30 INTERNATIONAL DEALER NEWS - JUNE/JULY 2019 SUPERSPROX Czech Republic, Poland, Ukraine [email protected] www.supersprox.com www.idnmag.com