I ware a camelback type hydration pack on my back when I group ride, and it doesn't even have the bladder in it. I use it to bring what ever I think I will need . Usualy throw some frozen bottled water- or bike bottles half filled and then frozen.these are good for long hot rides. I wouldn't care so much what other people think-- do it your way. Just make sure you can keep up, or better yet drop them. That usualy shuts up the bike snobs real fast.