I have a 3 liter Camelbak Mule that I use for mtn.bike riding. Hadn't been using it on the road bike, but now that our temps are getting cooler, will most likely start using it. Sure is easier than water bottles. Seems to be a big no-no around here to ride a road bike with a Camelbak, but then again, I'm using mtn.bike platform pedals, so it can only enhance my Fred status!