I've solidly arrived at the conclusion that I don't like SPD-compatible pedals. The PD-M520s worked fine enough for a few months, then got squeaky-- horribly squeaky-- and nothing could quiet them. They were replaced with iSSi Trails, which lasted longer, but got to a point where the cleats felt floaty even with the tension dialed up. So they went in a box. I made a very brief foray into Crankbrothers (two rides,) but did not like them AT ALL. Pedaling while standing was not confidence inspiring. Could be my shoes. Dunno. Then came the Look X-Tracks, which were excellent until about 5 days ago, when they got all floaty, just like the iSSi did. Tried both Wellgo and Shimano cleats without improvement.

So I grabbed my backup pair of Look S-Tracks (which are what I run on my road bike) and the improvement was fantastic and immediate. And in that lies the problem. My all-time favorite pedals were discontinued by Look about 2 years ago. I have two fairly worn sets and one nearly-new set on hand, but replacements are getting at the same time scarce and expensive. I bought yet another pair off of eBay this morning, but I feel like I'm just prolonging the inevitable. Somebody needs to think up a new SPD-alternative pedal before I run out of S-Tracks.