Originally Posted by swartzentruber
That's not the way it works for my BMWCCA club, and I think they follow national BWMCCA standards pretty rigidly. It is a good point for anyone buying an 05 that it's not usable for nearly as long as a 10. Our club's standard is to allow usage for one season past when the helmet becomes 2 generations old. In other words, you could still use a SA2000 until the end of the 2011 season (1 year past the 2010 generation), so if you buy a SA2005 right now, you'll be able to use it through the end of the 2016 season. If you are just starting and unsure if you'll stick with it, a half priced SA2005 might be the way to go, but if you are pretty serious, you might as well buy a 2010, because you'll get twice as long of usage.
Good point - one has to check with each club/organization about standards. This will be in the FAQ and technical sections associated with booking time at an event.