Knowledge is power. Doing the research beforehand gives you the power to control negotiations. If you're a buyer, knowing the model year and being able to identify all the non-OEM parts immediately puts the seller off balance. He knows he's dealing with a knowledgeable buyer and is far less likely ro try putting something over. Conversely, if you're selling, knowing all the facts tends to put a buyer at ease, facilitating the sale. Even if you're just showing your bicycle to a friend it's always good to have all answers, just so they don't show you up. on some item or fact. The bottom line is that nobody wants to appear ignorant about something they own or want to own.