This is for those of you who use SPD style MTB pedals, and have to do significant walking. I'm not too worried about the click/grind per se, but I am concerned about the longevity of my cleats.

I ride to a metro (subway) and take the train the rest of the way as a general rule. This means walking from the bike rack to the platform, and from the station to the office, and back. I change shoes once I'm at work, so generally no walking around during the day. All told, I probably walk a few hundred yards most days, and certainly far less than a half mile.

How much should I worry about damaging or breaking cleats walking on standard sidewalks? Escalators? Any surfaces to particularly watch out for? I'm okay with the 'slippery' factor, and I tilt my foot to avoid clicking on the marble when I walk into the building (don't want the guard to decide I'm damaging the floor) but my cleats grind pretty horribly on the concrete sidewalks, and I can't see walking on the outsides of my feet all the time.

I'm sure there might be shoes which would /protect/ the cleats a little better, but I have two pair, and both click/grind about the same. Pair #1 are relatively inexpensive Shimano MTB shoes, and pair #2 are some old AXO MTB shoes.

Am I worrying for nothing?