AL or Alloy                                  Aluminum

BCD                                                Bolt Center Diameter

B/O or BO                                   Bolt On

CASS                                               Cassette

CRMO or CR-MO                 Chrome Moly

DW                                                  Double Wall

FW                                                    Freewheel

HF                                                     High Flange

PV                                                      Presta Valve

Q/R or QR                                     Quick Release

SPD                                                   Shimano Pedal Dynamics

STI                                                      Shimano Total  Integration

SW                                                       Single Wall