I was going to say the Osprey HydraForm line is good, but they only go to 3L.
On a side note, I have an Osprey Raptor 14 I got used from the REI garage sale. The reservoir spontaneously started leaking. I emailed Osprey about it, and they actually sent me a brand new replacement. Awesome customer service. The packs themselves also come with a lifetime, no fault warranty.
Can anyone recommend hydration pack that is larger than >100oz?
I have a nice 100L pack now, but I want more water without using bottles.
Not sure if your concern is keeping hydrated, but go over to THIS THREAD and check out the links in Post #2, which have some links to articles on hydration or better yet "over hydration" and it's negative impact
I have wondered this too, a lot of my rides in the Florida summer heat are limited by my 100 oz pack. Mine is probably 7.5lbs or so full, and I can definatley feel the weight. But 55lbs of water , I'd be a strong rider after using that for a while !
Building off the sixbak idea, there is also a 100oz camelbak unbottle, I've used mine in addition to other packs, hooked it up to my cross bike for bike camping and can just toss it in a backpack without worry. Keep in mind your body can only uptake and retain a given amount of water, just because you have/drink a ton, doesn't necessarily mean you will stay hydrated. Start to drink up the two days before to aid retention.
I think that 6L unit is the way to go, I can make straps for it if I have to. lol
Again glad I could point you in the right direction. Even if I'm hydrated the humidity here is ugh and I can go through 3L's in an hour sometimes so, I here you on there is never enough water. Thus another option is night rides.