I know, blowing back usually takes care of 95% of the problems. My bite valve does tend to feeze solid at times because there's just a few drops of water left in there.
Hey, I just thought this was more of a convenience item rather than necessity, there's been times I only had a minute or so and could use a quick drink before we head off again, and if the bite valve is solid it can take some convincing to get flowing again. I've found that anything I can do to stay hydrated is a plus for me. I've been on more than one ride and not drank enough and felt like **** the rest of the day. Add dehydration to the altitude for us flatlanders and it can make for a miserable experience.
Just wanted to pass the word on a product, enjoy .