Originally Posted by
Shimagnolo
Get the double-sided SPD's and be done with it.
I currently have the 520's, 540's, and XT's on 3 of my bikes and can't tell the difference between the 3.
Then I have the single-sided A-520's on a 4th bike and detest them.
They are a PITA when you are trying to get a quick start in traffic.
They will soon be replaced with a double-sided model.
Since there is no difference in function, save yourself money (like me) and get these:
http://www.amazon.com/Shimano-PD-M52...8516659&sr=8-1