The history between STM and the competition world is a long and emotionally rich one. Every product is born on the race track, thought of and produced to compete; only when it passes the final test in a competition is it mass-produced and commercialized all over the world.

By racing at the top level in many different categories STM is able to continue the evolution of its products to make them more and more competitive, turning the riders’ feedback into innovative solutions to be applied to the industrial production.

The first test of an STM slipper clutch on the track dates back to 1996 and took place in Brno with Pierfrancesco Chili. In the same year the association with Ducati marked the official debut of the STM clutches in competition and started the long series of extraordinary successes, such as the conquest of the World Superbike Championship in 1998 and 1999 and of the AMA title in 2001 and 2002. In 2003 STM introduced in the World Superbike the slipper clutches for the Suzuki and Yamaha wet systems and made its debut in Motocross and Supermotard with the clutch for Honda CRF450. In 2004 STM became World Champion with Stefan Merriman in the Enduro World Championship.

From the World Champion to the non-professional rider, the STM technology has always been close to those who look for the best possible per

Slipper clutch set up: primary and secondary spring
The STM slipper system is produced with highly advanced materials and technologies allowing the rider to carry out several adjustments through the replacement of primary and secondary springs. The secondary spring has been designed to tune the slipper system of the STM clutch so as to give the possibility to adjust the engine brake. The function of the primary spring is to compress the disc pack. Should you like to obtain a different calibration to increase or decrease the engine brake we suggest to act on the secondary spring. For a customized advice on the calibration of the clutch please contact a skilled technician or the STM technical department. If the clutch was correctly mounted the closing of the central nut has no effect on the slipper system. Please contact your favourite retailer to buy additional springs to adjust the set up of the clutch and to obtain the adjustment which better suits your driving style.