I've replaced my 914A MMM once in four years. It was definately my fault. I was using the front of the deck as a leveling blade (does work well, don't you know) and a few large driveway rocks got under the protective covers of the belt. Sure as shootin', the belt just didn't like the uninvited guests. The belt snapped clean, almost like a knife cut, but the rest of the belt looked great; no cracks or age type drying. Yes the belts are expensive, but the 914A has proven to be a real work horse for me.