Full Speed Ahead Gossamer Tandem Front Crankset - 175mm Single Speed 42t 130 BCD Full Speed Ahead MegaExo Spindle Interface BLKFull Speed Ahead Gossamer Tandem Front Crankset 175mm Single Speed 42t 130 BCD Full Speed Ahead MegaExo Spindle Interface Black. The FSA Gossamer Tandem Crank Bottom Brackets sets feature cold forged AL6061 T6 aluminum crankarms with a MegaExo spindle. Shimano and SRAM 10 Speed compatible 2 Bottom bracket spacers allow for adjustable chainline 35. 0mm Tandem specific braze on front derailleur clamp included with rear cranks Cold forged AL6061 T6