I don't carry a water bottle, and certainly not a water bladder, when I ride at WRL. However, I have been known to carry a bottle on the Plano East Side Ride, during hot weather, mainly for hydration during the last 10 miles of the ride (The hottest part). Ordered the hydration system shown in the below photo: https://www.amazon.com/Blue-Desert-SmarTube-Hydration-System/dp/B000GM6LWS/ref=s r_1_1?ie=UTF8&qid=1494877308&sr=8-1&keywords=smartube. The kit contains adapters for both small-mouth plastic water bottles and standard bike water bottles. My intent is to purchase a chilled bottle of water at the last East Side Ride rest stop and put it in the small bag on the back of my bike's seat. That way I don't have to carry extra weight around, until near the end of the ride.
 
 

Quote from JimFPU on May 15^th, 2017, 4:10pm:

 
Yes, a very small, light-weight one.  
 
http://t-cycle.com/fastback-hydration-packs-c-6/storage-packs-c-6_36/fastback-ca rbon-slim-seatback-bag-p-95.html. Fits three of my bikes with carbon seats. Easy off and on, so I only need one bag for all three bikes.

Quote from JimFPU on May 16^th, 2017, 5:02pm:

 
It's a small bag, believe me. The bike had one of those honking big bags on it when I received it. Replaced it immediately. I will never desecrate any of my recumbents by installing a surrey top.  

Quote from MrWizard on May 16^th, 2017, 10:22pm:

 
SmartTube hose assembly w/plastic bottle adapter: 2.45 oz.
 
Small Camelbak bladder (empty) w/hose assembly: 6.85 oz.
 
I'm only going to be carrying a bottle of water for the last 10 miles of the East Side Ride. Filling a bladder at a Stop & Go is a pain in the azz,  besides it won;t fit in the bag along with my other assentials.

Quote from JimFPU on May 18^th, 2017, 8:43pm:
Besides, those Flevobike tops are so cool looking on a Quest.  

I had to check (because I hate camelbacks) but I love the euro equivalent from Geigerrig http://a.co/8uApHKQ    mainly for the reason you cited .. and its a million times easier than a camelback to fill and clean  (you just turn it inside out and toss it in the dishwasher)  
 
The 100oz bladder + cut down hose and not including the pressure bulb which I don't take with me  was 4.20oz  
 
Not that it matters to me;  All of my main rides are north of 50 pounds.  
 
Quote from jayg on May 17^th, 2017, 2:11pm:

Quote from jayg on May 18^th, 2017, 10:28pm:

 
The pic is on the Web...it's out there forrrreeeeveeerrrrrr!

Quote from MrWizard on May 19^th, 2017, 7:12am:
Doug, thanks for posting that link.  I had seen that bottle a while back, and lost track of it.  What a great idea to have the water pressurized.  I'm really satisfied with my 1 liter Camelbak bladder, but it would be super if the water could be shot into my mouth.  Reminds me of wineskins of the 1970s.  

Quote from reever on May 27^th, 2017, 5:44pm:

 
I found out the same thing today. The bite valve is what is restricting the flow. Just installed a CamelBak bite valve on it, and now it's working like it should. The SmartTube tubing has a smaller diameter than the CamelBak tubing, so I had to heat it up a little to get the valve on.