The Dirt Tricks KTM Rear Sprocket was designed and patented by Dirt Tricks president and engineer Greg Burns in 2002, using his knowledge of aerospace steels, heat treatments, as well as FEA stress analysis. Being an expert desert racer, Greg became tired of changing aluminum sprockets every two months. His goal was to create a sprocket that would last an entire season of hard riding, yet be comparable in weight to aluminum. Thus, the Dirt Tricks sprocket was born. It required two years of development and testing, but the end result has proven to be the toughest, most durable off-road sprocket available KTM Standard Rear Sprocket Fitment: KTM: '91-'16 All 2-stroke models 125cc and up '99-'16 All 4-stroke models 250cc to 690cc Husaberg: '00-'14 All models Husqvarna: '14-'16 All KTM based models KTM 85 Rear Sprocket Fitment: KTM (428 chain):'04-'16 SX 85/85 Big wheel '08-'09 XC 85/105 '07-'11 SX 105 KTM Adventure Rear Sprocket Fitment: KTM (525 chain): '03-'06 950 Adventure/Adventure S '06-'10 950 Super Enduro R '05-'13 990 Adventure R/Adventure S KTM ATV Rear Sprocket Fitment: KTM (ATV): '08-'10 SX/XC 450/505/525