*Ramps on big rings are specially configured for combinations: 50/34, 52/36, 52/38, 53/39T*34t Premium Series inner chainring is not compatible with power meters which use circular spider (SRAM Quarq, Power2Max, etc) . For those power meters please choose our Silver Series 34t inner oval.*If you wish to use other configuration it will also work, but shifting will be slower and may require more "adjustments" of front dérailleur to be acceptable. Also remember that front dérailleur can only accept max 16T difference between 2 chainrings - this is how Shimano and Sram designed them.*Absolute Black always recommends using a new chain when fitting new chainrings.