Quote Originally Posted by nscrbug View Post
I'll freeze it for my Saturday morning ride and see how long it lasts.
Yeah, I'll be curious to see if this works for you. Solid ice keeps frozen longer than cubes (less surface area), so it should help. I also just remembered that when I got the best results, I had a half frozen solid mass in there WITH ice cubes to the top and then filled in with fridge-cold water. Kind of a PITA, but better than drinking hot water.