[squirrel_hunter]

Can someone please explain to me how they work?

I have spent quite sometime, tonight for instance, arguing with bikes, wheels, and their spacers. Its an argument that I always win, it just takes too long. So it got me thinking those racers can change wheels quite quickly and they have yet to resort to evolving an additional set of arms (don't get me wrong an additional set of arms would be very useful I just don't fancy buying all new t-shirts just yet). I understand that they use captive wheel spacers to help them and I have seen them available for many bikes. But I was wondering how they work, how they are fitted, and why they are not standard?