Lou's ideas on "what to do" with your bikes are good.
Unless you have something REALLY special, few museums will be interested. A typical museum will simply sell the bike you bequeath to it to pay its own expenses. Museums have their own ideas about what to collect and they're probably different from yours. And wouldn't it be better for your rides to get ridden?
My advice is to educate your family about why your bikes are special and valuable, document them (so the info is available when you're not), and be sure you have a will and executor who knows about it too. If your bikes find buyers who appreciate them when you're gone, your heirs will be paid fairly for them. If your collection is liquidated through an estate auction, your heirs will wind up with bottom dollar for the bikes. Someone else will buy 'em cheap and sell them to the collectors who weren't at the auction.
And this kind of chatter sure indicates that people aren't out riding enough!
David Bean
Arlington, MA