Hydration pack fits a certain "crowd"? Really? Like sucking on a bottle puts you in a certain light?

Gave up on CO2 for a mountain bike a long time ago, got them when I raced, and didn't use them for long. Simply unreliable; a broken CO2 inflator or empty cartridges are pretty damn useless 20 miles from civilization. Plus you always have to remember to buy/replace the empties. Get at least the large cartridges for mountain tires, 16g if you must use them, 25g even better. At the pressures you say you run can't imagine the 12g would work well. Here's a chart I noticed http://www.genuineinnovations.com/im...on%20Chart.jpg.

I don't use a pack on my road bike, and do use a CO2 (but it's extremely rare for me to flat on the road and I can always call a taxi), I really hate rattling road frame pumps or dealing with making it not ratlle. Plus side to the frame pump on a mountain bike is it has given me several free pumps over the many years . Get an extra velcro strap or something if you gotta hang it on your frame.

Pump in a good pack is the way to go IMHO, lose the bottles (and the crud that can get on them), take the weight out of pockets/off the bike, plus gives you enough storage for food, safety breaks, change in weather, real tools, more water, etc. Topeak Mountain Morph is my favorite, especially friendly to presta valves with it's mini fill hose and foot peg.

ps 2 tubes plus patch kit for the mountain bike (actually, same for road bike)