The 1x is purpose-built for cross country riding with a 1x9 drive train. If you are running 1x9 and don"t need a bash guard, this is the ticket. No more homemade contraptions needed!Purpose built for cross-country riding with a 1 x 9 or 10-speed drivetrainIncludes Spacers for fine tuning chainline adjustmentItem SpecificationsChainring BCDN/AmmMax Tooth40teethRing SetupSingle