Race Face Bosch Gen4 104 BCD Spider The Race Face Bosch Gen 4 spider allows the use of Race Face 104 BCD rings on Race Face ebike cranksets (52mm chainline). Features This spider is only compatible with Bosch Gen 4 Performance Line CX motor Any Race Face 104 BCD chainring will mount securely with the included hardware, including the Race Face SHI-12 speed rings Aluminum SPECIFICATIONSDirect Mount Type Direct Mount Bosch Gen 4Designed for ebike Yes Chainring BCD104MFG#F10025 | Race Face | Raceface Bosch Gen4 104 Bcd Spider 4-Bolt 104 Bcd Aluminum Black