I got this pack to use for a few hours of biking, but I use it for light day hikes now too. Its small enough that you can take it out for just a few hours of riding, but big enough that I can use it for 4-6hrs when I'm packing light. With the 100 oz reservoir you got plenty of water and the compartments inside are actually useful unlike some packs. The helmet carry works great for XC helmet, I can't say how well it works with a full face though. Also, the hydrapak reservoir is a lot easier to clean out than a camelbak. Great pack, but I will say it feels like it sits too low on my back and I can't get the fit just right, but that could just be my personal preference.