Dirttricks Australia Sprocket Sherco (12) : SE-R 250/300 2T (21->C). SEF-R 250/300 4T (21->C).

DBR front sprockets are constructed of through-hardened, shock resistant die steel.  Most front sprockets sold today are "case hardened", meaning that only a thin layer of steel is hardened.  Below that layer is a core of soft steel.  DBR front sprockets are heat treated to as hard as bearing races all the way through, giving them the ultimate in toughness and wear resistance.  How can we have such hard material without being brittle?  Shock-resistant die steel is the answer.  This is the same steel used to punch hole through 1" thick plates of steel, on high speed punch presses.

 To Suit: SE-R  250/300  2T (21->C).   SEF-R 250/300 4T  (21->C).