Originally Posted by mander

The two spd cleats i'm familiar with are the SH51 (black) and the SH56 (gold). The gold cleats are designed to unclip vertically; I have no idea why. They are an optional accessory and a lot of the fretting about spds seems to come from people who have heard of these cleats and think, like me, that they sound like a very bad idea. But like I said they're optional accessories, not the default cleat you get with all spds. I've never heard of people unclipping vertically with SH51's, the black cleats, though for all i know it still could happen; and they come with 520's and work with all SPD pedals.