The 104mm BCD 3X model allows use of a standard 3x chainring configuration (i.e. 22/32/42T), or the use of two chainrings and a bashring (i.e. 22/32/Bash).
The 104mm BCD 2X model allows use of a traditional 2X chainring configuration (i.e. 22/32T) - no bashring or third ring capability.
The 120 BCD spider allows use of either 26/38T or 28/42T 2X chrainring configurations.
The Boost 104 BCD spider is intended for bikes with a 12x148mm Boost rear spacing only.
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