New drive belt is released together with TA05-IFS R Chassis Kit and that can used as a spare gear for its drive train (37T-18T-37T pulleys). It can also be combined with TA05 series drive train (36T- 16T-36T pulleys) if improvements suggested in TA05-IFS R guide are followed assuming ITEM 53988 Ball Differential Pulley (37T) and either ITEM 53989 Center Pulley (18T) or ITEM 54050 TA05-IFS R 18T Center One-Way are installed.