Originally Posted by
chenghiz
There's 2 kinds - SPD and SPD-R. SPD is the standard 2-bolt cleat you see on MTb and Chrome and so on, the more 'walkable' kind. SPD-R has a 3-bolt cleat and is the 'road' type - more secure and better power transfer (from what I understand) but walking the the shoes is awkward.
SPD-R is also a two bolt system, but it is no longer produced. Shimano adopted the LOOK style 3-bolt cleats, and for a while they actually used LOOK Delta cleats. The newer Shimano road pedal is called SPD-SL