>>I won't ride in a pace line with you unless I trust you.<<

That must limit your fast ride participation. I don't get a chance to audit my paceline mates before every hard group ride. And sometimes, yes, they do stupid **** that scares the hell out of me. But not too often fortunately.

Another paceline no-no: you know that pothole you'd normally swerve around to avoid @ 30mph? When you're in a paceline DON'T. Some idiot did this in a paceline I was in last Fall and nearly took out a dozen riders behind him. Next time you see that bump remember that and SUCK IT UP WHILE HOLDING YOUR LINE - if there's a wheel behind you @ 25+ mph. The faster the paceline the more important this becomes.

And by the way, I've NEVER been in a FAST paceline where there was ANYTHING resembling idle conversation. Once speeds exceed 25mph or so it's like the oxygen masks have dropped from the cabin ceiling and everyone's pretty focused.