When in a pace line what is the distance/time the lead rider should give to alert the other people in the pace line. One of my riding friends doesn't give us a clue until a second before. I've tried to signal as soon as he does, but many times have found myself in danger by taking my hands off the drops, because we're already into the hazard. I asked him to give us more warning, but he says his eyes are not that good and he will have a new pair of glasses next week. He is our strongest rider and tries to pull all he can. If he doesn't have a new prescription next time we ride, I think I'll kindly tell him the truth and hopefully he'll understand and won't pull. But I'd still like to know what riders consider an appropriate distance/time.