Federal bbs solid sprocketthe federal bbs solid sprocket is machined from high quality 6061 t6 aluminium and provides the ultimate in durability and strength its 24mm central bore means it fits straight on to federal cranks and all other bmx cranks that use this spindle size features material6061 t6 aluminium tooth size 18 24mm bolt drive centre bore 24mm weight 105g 25tbuyfederal componentsfrom chain reaction cycles the worlds largest online bike store