Just started using the camelbak for uplifts etc again, for the convenience of having tools and water and that to hand... My pack's fine but I'm thinking I'll get a smaller (cheap) one and just fit it out for the job rather than always swapping stuff around (or, more likely, carrying tons of stuff I might want on an XC ride but will never want on the dh bike).
So... What's small-ish (low water capacity is fine, it'll not have much in it), has space for just minimal kit like a tube, multitool and pump... But more importantly stays where it's put, isn't bulky, and has good capacity for attaching a fullface helmet? Oh yes, and not much money!
I was thinking a camelbak rogue for minimalism but it seems to lack external straps?
Dakine Drafter or one of the smaller Osprey packs. They have external helmet straps.
Edit: actually IIRC the Osprey ones have a strap for vented XC helmets. Evoc packs have ones that work with full face helmets, too.