My right-hand SPD cleat makes a clicking sound every time I pull up or push down on the pedal, like it's loose in the SPD mechanism. It doesn't unclip itself, but it does this on all my SPD-equipped bikes, so it's not the pedal, and adjusting the pedal tightness doesn't seem to help. It's only the right-hand side, but I unclip my left foot at the traffic lights, so it shouldn't be the right cleat which has worn. Any suggestions as to what's going on?

Thanks in advance.

Sounds like a worn cleat to me....do you walk around in it? ( I walk around in my SPD's a lot and have worn out a set of cleats that way)

Yes, I do walk a fair amount in it, so that's probably it, but that still doesn't explain why only the right-hand cleat has worn, unless I have a lopsided walk. Come to think of it, I probably do...

Anyway, I've got a set of spare cleats that came with one of my sets of pedals, I'll fit them later and see if it helps.

Thanks

I wonder if it could be the bolt moving around in the shoe?

My SPD cleats creak quite a bit, but it's because the oval rim of the cleat is wearing against the body of the pedal (PD-M959). There is a shiny spot on the cleat and pedal where it rubs. It helps for maybe a ride if I apply grease. Probably not your issue though, as yours is happening on multiple pedals.

+1 Definitely check that. It's not a good feeling when they come completely loose.

If it's happening on all your bikes, I also suspect your cleats are worn out.