Model No FD-R58-F FD-R58-BChain Ring Double Cassette Compatibility 11 Top Gear Teeth 50-56 T Capacity 16 T Route Type Down Pull Chainstay Angle 61-66 Mount Type Brazed-on Band Chain Line 435mm Band Diameter - & Phi;349 & Phi;318 (1) Front Clamp Band Aluminium cold forged Rear Clamp Band Aluminium cold forged Outer Link Aluminium cold forged Inner Link Aluminium cold forged Chain Guide Steel CP "CENTOS11" Average Weight 95g 105g Compatibility Shimano Ultegra 6800105 5800 compatible Remarks (1) -Clamp spacer (Y-FDR06) allow the derailleur to be & Phi;318mm frame tube Without ring spacer the derailleur mounts to & Phi;349mm frame tube