Our aggressive 12" rear tire paired with the skinny 14" front tire set on lightweight aluminum rims. We include spacers to work on both the mx and sx bikes. These include the 428 48t sprocket and both wheels have the 190mm pit bike rotors. You will need an extended arm and forks that will accept these monsters! Sorry no substitutions for the sprockets but we do offer a 60 and 76 tooth for you torque guys like me :-)
