M324 SPDs come with stupidly heavy..... steel cages. The bolt holes for securing them to the body are 52mm apart on one side and 50mm on the other. Is there any kind of standard for these?
no, not even on a single pedal....
FWIW PD-M323 have similar problems but without even chrome plate. The steel cages help the pedals flip upright, but otherwise are overkill. They stick out too; I have been known to clout them on things when using the SPD side.
It isn't that difficult to make aluminium plates to replace these, and without the quill end, you can service the bearings without messing about with the pedal cage; much better.
cheers