Founded in 1983 by mechanical engineer Thomas Fehring, Structure Mechanics Corporation designs and manufactures racing clutches and sprockets for small-engine applications. The Cincinnati company began as a consulting firm in finite element analysis before bringing that engineering work into American-made karting products in 1989, including its patented Vortex clutch system. SMC says it has produced more than 4,000 axle clutches, tens of thousands of engine clutches and hundreds of thousands of clutch sprockets sold on five continents.