Originally Posted by Carbonfiberboy

Group rides are high stakes games. A few milliseconds of inattention can take you or someone else down. You shouldn't be allowing more than a wheel width gap to open. If you're having bike lengths open, you aren't paying anything like enough attention. You can't do that. If you were in the middle of the line, you'd be splitting the group. Keep your cadence up so you can respond, and watch what's happening.