Check your cleat bolts and pedal tension setting. After a couple of years though sounds as though the cleats need replacing.I've got some DHB mountain bike shoes which clip into Shimano DX M647s. Had them for a few years but now my left cleat is un-clipping occasionally when the foot is on the rise. I'm not twisting out, but it just feels looser than they used to. Anything I can do to get it back to normal or do I just need to buy new gear? And if so, what needs replacing? The cleats?