From what I know, M430 is 9 speed Alivio and M410 is 8 speed Alivio. And oddly enough, from a quick read on niagaracycle, it looks like M410 cranksets have riveted chainrings (EDIT: this may not be true) while the M430 have removable chainrings. However, friction shifting is a little more difficult with a more narrow 9 speed chain. I found some R443 cranksets which were apparently non-series components that were 48/36/26 with a chainguard, nice combination but they were 9 speed. Those non-series components make me laugh sometimes because I wonder if they're spec'd by manufacturers who'd rather keep the quality levels secret from their customers or competitors. I'm not sure what the case is there.

I read someone took the time to measure the difference between the width of the chainrings on 9 speed cranksets and 8 speed cranksets and also the space between the chainrings. They were the same except the ramp, pins were spaced differently. This means an 8 speed chain could work apparently well enough on a 9 speed crankset although not perfectly. The only thing is deciding if I'd be willing to sacrifice the perfect shifting on the 8 speed to get the 9 speed for the advantage of the chainguard and the 48/36/26 chainrings.

Does anyone know by chance if the "Supershift" chainrings on the Sugino Impel 150x are comparable to the shifting on the Shimano models?

EDIT: Here's a weird question. Do any of you think it would ever be worth it to try to take out and replace the chainrings on a riveted chainring crankset if they were ever worn out? I mean what kind of tool/technique would you use to grind or drill the chainrings out of there?