Quote Originally Posted by liza View Post
At the time I was unsure if it was "rude" to follow a stranger like this -- would my behaviour here fall into the same creepy/annoying category as this white-bearded guy???
It doesn't make you creepy (Geonz's answer is great) but it put you at a potential risk of hurting yourself, especially if 1) the guy doesn't know you're there or 2) the guy doesn't know how to draft someone else (and don't be fooled by the fancy clothes and bike, it doesn't mean much).

If there's a hill and he stands up (or sits back down), his bike will sort of "jerk back" (actually it's only slowing down while you keep pretty much the same pace) and you can bump into his wheel. Or if for some reason he brakes suddenly or even coasts, at the moment when you were not 100% attentive, you can also touch his wheel (or worse). He'll be fine, but you'll go down.

I don't think it's especially rude to draft off another roadie, but I find it really important to let that person know you're there. I'd really be mad if I someone drafting off me crashed in traffic because I didn't know they were there.