Got any pictures, [MENTION=193959]FastJake[/MENTION]? I would assume you'd be building with good tension and stress-relieving, so the wheels ought to be lasting a lot longer, regardless of your track-standing. If the spokes were breaking at the elbows, I'd wonder if they are from a batch where there is too much length between the head and bend, so that they're not well-supported against the hub flange.