I've been doing some fairly aggressive group rides here in Irvine, CA there are always some CAT 1/2 guys and fairly often you will see a domestic pro or two. But there are also lots of slow(er) Cat 5 riders such as myself. The peloton is huge (30-100 people) and not organized at all (typically the fast guys just tow us around) there is no paceline - the peloton is very similar to some of the crits that I have done.

Typically we ride in a huge pack maybe three people wide so there will be 3 people in front of me, I will be on one of their wheels and then 2 people next to me will be on the other 2 wheels. Say I'm on the far left and the pack slows a bit, I will stagger myself slightly left (2-3") to "grab" some wind and slow down (never overlapping the wheel in front of me). At which point a lot of times someone will jam themselves between me and the person to my right and attempt to "push" me left and take the wheel I have been drafting. But sometimes I will just be following the wheel in front of me and people will try to take it away from me.

Also, many times someone will jam between me and the person next to me even if there isnt a wheel in front of them to follow and there really isn't enough space for them to fit there. This happened twice to me today, one time I braked, and almost clipped the guys rear wheel with my front as I was moving backwards and he was swerving into me.

Is this normal behavior? Do I just need to be more aggressive? I find that if I "lean into" them and not move at all they tend to back off. But since this is a group ride I am not really prone to being this aggressive.