Pardon me if this newbie question has already been asked and answered, but I could not find it by searching and browsing.

When riding solo, I will occasionally be passed by a pace-line and I'll speed up to hook on the back. If it's a recreational ad-hoc group with non-matching jerseys, I'll then ask if its OK to join in, and so far I've been welcomed. I'll then either participate in the rotation or drop if I can't maintain the pace.

The question I have is whether it is generally frowned up to do this with a team or club paceline (with matching jerseys), particularly if they are hammering. If the group is riding at a conversational pace, then it doesn't feel like my asking a question is an imposition and I've been welcomed as above. On the other hand, if everyone is breathing hard near threshold, then I don't think they appreciate having some random self-invitation shouted from a stranger in the back, so I don't say anything.

I've typically held back at least 3 ft off the last wheel for while and then dropped when the leader pulls out; however, it occurs to me that even this may be too intrusive.

So the question is should I generally avoid hooking onto team pacelines? And the follow-up question is whether the answer changes if I'm touring out on the open road versus a circuit like El Dorado.

Reason I ask the follow-up question is that I was out on the road west of Ojai and the attitude was hey if you can hang with us and the olympian pulling this thing then feel free.