prevents the rear wheel from locking up , eliminating " hopping " and improving the performance and handling - especially under deceleration and cornering . The main purpose of a slipper clutch is to prevent engine over-revving and rear wheel hop ( or chatter ), especially under hard braking . It does so by partially slipping until an engine ' s speed matches with the vehicle ' s speed . A straightforward concept it may be , but designing and manufacturing products to achieve that goal is anything but straightforward . The three most important characteristics needed in the design , materials and production processes are quality , quality and quality . The slipper clutch consists of two bases , one with dog clutches and ramps with ball bearings , a splined hub and clutch plates . In normal operation , the dog clutches mate , driving the transmission . When a back torque comes from the transmission , the splined hub slides up the bearing ramps , disconnecting from the clutch plates and allowing a limited " slip " between input and output . It will partially disengage or " slip " when the rear wheel tries to drive the engine faster than it would run under its own power . The engine braking forces in conventional clutches will normally be transmitted back along the drive chain , causing the rear wheel to hop , chatter or lose traction . This is especially noted on larger displacement four-stroke engines , which have greater engine braking than the company ' s two-stroke or smaller displacement counterparts . Slipper clutches eliminate this extra loading on the rear suspension - giving riders a more predictable ride and minimising the risk of over-revving the engine during downshifts . Slipper clutches can also prevent a catastrophic rear wheel lock-up in the case of engine seizure . Generally , the amount of force needed to disengage the clutch is adjustable to suit the application .
CLG clutch
By transferring the technology developed , and the experience gained on the track of slipper clutch designs for massproduced models , the era of anti-friction clutches began and STM was very quickly accepted as an innovator and leader of a nascent but important niche market . While Honda ' s ill-fated NR500 ( the New Racer 500 - or , as many nicknamed it at the time , the " Never Ready " 500 ) failed to realise Honda founder Soichiro Honda ' s dreams of marking the company ' s return to racing by " sticking it " to the two strokers , much of the then advanced technology deployed on the NR500 has passed into the mainstream . In the case of the slipper clutch , its moment came in 2003 when STM took the critical step of applying its anti-skid technology to oil-immersed clutches for the first time and BOOM ! That would see the slipper clutch concept take its place alongside many of the other advanced ideas seen on the experimental NR500 . Embracing the apparently unlikely environment of the wet clutch with anti-slip technology greatly extended STM ' s market opportunity , and collaboration with the Honda , Suzuki , Yamaha , Kawasaki and BMW teams has resulted in the development of cutting-edge products that combine component durability and reliability with precision and performance . In that same year , 2003 , STM also made its slipper clutch debut in the world of Motocross and Supermotard - receiving instant acclaim and immediately contributing to many victories . In 2017 , STM Italy achieved UNI EN ISO 9001:2015 standard compliance - providing its OEM , distributor , dealer and race shop customers and riders with the confidence of knowing that its products are backed by the ultimate Quality Management System certification . Materials excellence is central to the reliability and performance that STM achieves , using Ergal ( zincaluminium alloy ), low silicon content Anticorodal alloys with outstanding mechanical properties , electrical conductivity and corrosion resistance , stainless steel and titanium ; all machining is on inhouse CNC mills . In a world of profound technological transformation , the STM vision will remain at the forefront of antifriction technology development , anticipating and shaping the future with innovative solutions and market-leading manufacturing quality for MotoGP ,
Special Dark Edition EVO-GP - dry conversion kit for Ducati Diavel
Team HRC riders Alvaro Bautista and Leon Haslam
WSBK , Motocross and Supermotard racers . The company says it will also now start to leverage its competencies and reputation as it expands its aftermarket performance parts and components programmes through continuous improvement , one step at a time . KAIZEN .
STM Riva Presso Chieri , ITALY Tel : + 39 011 012 1521 contact @ stmitaly . com www . stmitaly . com
STM at EICMA 2019
24 INTERNATIONAL DEALER NEWS - OCTOBER / NOVEMBER 2021 www . idnmag . com