Hi C4C!
Looking at your questions, I'll take them one at a time and tell you what I do. Others will surely do differently, but this is how I go about it for my self-supported, extended desert tours where potable water is often unavailable due to alkali contamination (which cannot be filtered), requiring me to pack my own for use in sometimes extreme heat (air temps of 125°F/52°C and ground temps of 140°F/60°C in extremely low humidity).
1. How much water to carry
For the conditions above I carry as much as 26.5l maximum, which also means 26.5kg as well. I carry 6.6l on the bike; two 1l Zefal magnum water bottles in cages cable-tied onto my steerer where they do no affect the handling. The remainder is carried in three 1.5l bottles in Blackburn B-52 Bomber bottle cages, two inside the main frame triangle and one below, all attached to Thorn's frame bosses.
The remainder of my water is carried in two 10l MSR Dromedary water bags. This has not proven to be very satisfactory for my needs, as I have found my bags quickly developed a very foul odor (smells like scorched rubber) and taste (same, with a chemical aftertaste). I have been careful to always dry the bags and to not store water for extended periods in them, and no mildew is present (one bag took awhile to develop the smell and taste; the other did so overnight). Despite MSR-recommended treatments with hot water and baking soda, the solution is only temporary and returns almost immediately. Online reviews indicate this sometimes happens, and MSR assures customers it is not a health hazard. I understand it may be due to bromine in municipal water supplies, and I live 0.8km south of the water plant, but the new bag developed the problem using only bottled water, so I view my MSR Dromedaries with mixed feelings.
2. Back to where to place them
If taking only one 10l bag, I place it atop my rear rack and lash it securely alongside my tent/footprint and the dry sack with my sleeping bag, pad, silk bag liner and air pillow. If I take both bags and no trailer, then I place the dromedaries in the bottom of each rear pannier. If I am taking the trailer, then the bags go in the panniers on the trailer. The bags are not wholly waterproof over time and on rough roads, water will express itself through the walls of the bag, raising humidity inside my waterproof Ortliebs. I fear it could precipitate mildew formation over time, so that is why prefer them atop the rear rack, outside the bags. If only one, I will often align it lengthwise on the rack to keep weight low and serve as a "base layer" beneath the tent and sleep system sack. I sometimes place the crosswise, depending on the load. It seems to work out ether way, but I make sure to bleed off all excess air in the Dromedary so the water doesn't slosh and affect handling. It also makes a more compact load, becoming only as large as the water it carries.
On all ordinary tours, the 6.5l on bottles mounted to the bike itself is plenty.
In short, where to place another 10l+ of carrying capacity on bikes with no front panniers and no trailer?
Dunno; that's going to be 10kg (1l fluid water capacity=1kg of mass + the container), a lot in one place. When taking less than maximum capacity, I sometimes fill ech 10l MSR Dromeday partly full and place one in each rear pannier for better handling. The 10l models weigh only slightly more than the 6l or 4l models, and allow you to roll the excess, taking minimal room if not filled to capacity. Perhaps they could be carried in a frame bag or lashed to the frame, but then you would not have room for conventional bidon mounts. I should note a 10l bag is large enough capacity to fit with a shower adapter and will provide a nice shower; a dark-colored bag will heat quickly in the sun and makes a nice way to end a dusty day before turning in for bed. If mine is less than full, I try to top-off my bags at a stream, creek, or cattle trough just before making camp, being mindful to purify the lot 1l at a time with my Steri-Pen Classic UV water purifier. Even though it will soon be "shower water", I'll be drinking from the same bag later, so the contents have to be potable and safe.
no hose clamps. Dan - I agree with that 'nordicgroup''s sentiment of not using hose clamps.
<nods> Agreed, c4c. Hose clamps can fail in a variety of ways, none pretty. I still pack a couple in my kit for emergency use, but they're only for that.
n short, to begin with we want capacity for 18l between us...Back to where to place them.
Here's a suggestion to consider, though it might take some creative sourcing and mounting:
• Two 1l Zefal Magnum bottles in CatEye nylon cages on the steerer = 2l.
• Two Salsa Anything cages, one on each fork blade, holding 1.5l bottle each = 3l.
• Three Blackburn B-52 Bomber cages or two Anything cages on the three Thorn frame mounts, each carrying 1.5l = 4.5l
That adds up to 9.5l each bike. If you had to reduce that to two Anything cages for 1.5l bottles and 1 conventional cage with 1l Magnum bottle under the BB, that would reduce capacity to 9l. In either case, two bikes setup like that would meet your desired 18l capacity between you.
• A rolled-up 10l bag apiece (remember, the weight is little more than the smaller-capacity versions) would provide extra capacity when needed and allow lashing to the rear rack at whatever partial or full capacity. At maximum capacity, you
could carry as much as 19l per bike, virtually doubling your capacity and that might be nice if you need to carry it for only short distances.
One concern I have about putting a lot of weight in bottles on the lower suspension stanchions is how it might affect the fork's damping action. That's a lot of mass in unsprung weight, drawing on my automotive background. Andre will surely have some thoughts here as well. As for mounting the Anything cages to the fork lowers, I'd be inclined to use the Tubus clamp-on lowrider mounts. Though it would be sort of expensive, it would be a lasting solution that I believe would remain secure, provided they were torqued to spec and secured with LocTite. I urge caution not to overtighten any clamp to a point where the fork lowers could be distorted.
Reading around regarding centre of gravity, it seems the short summary is: when you're slow you want it low, when you ride faster it actually gets easier when it's higher.
Though it relates to frame design and is directed to how bottom-bracket height affects handling, an article written some years ago by Rivendell's Grant Petersen called "The Stilt-Step Factor" speaks to this to some degree. A few copies are still around on the 'Net. Thorn's relatively high-trail geometry does especially well carrying a lot of weight at the rear. Low-trail bikes tend to do better if the weight is carried on the front and neutral handlers don't care so much one way or the other.
As for weight placement, I try to get mine as low and as far toward the center of the bike (in every way, side-to-side and fore-aft) as possible to minimize the effect of mass on handling. Yet another option: I sometimes pack one MSR 10l Dromedary crosswise atop my Thorn Expedition rear rack forward mounting tangs, *ahead* of my rack-top load. This way, it is as far forward as possible, while still being as low as possbile outside the bags, about he same position as a true saddlebag, but lower and more stable. Depending on frame size, that space may be going to waste otherwise. Doesn't interfere with my legs on my 590M Nomad, and places the mass very close to my own so handling is little affected.
As for the fuel bottle (freeing up one more spot for a water bidon), I carry mine inside my bags. I have a Sigg .5l and a Brunton 1l and choose between them depending on how long I'll be gone away from resuppy. I use a SIGG gasketed cap on each bottle and have never had fumes escape or collect in my bags. I most often burn white gas (naphtha/Coleman fuel) in my multi-fuel stove, and occasionally automotive unleaded petrol in the areas where naphtha is unavailable. The stove will also burn kerosene, No. 2 heating oil, and JP-4 jet fuel. I have seen some clever solutions on long-wheelbase derailleur bikes where the fuel bottle is carried horizontally. Depending in size, I have also seen them carried under the saddle rails in a bottle cage using a tri-athlete's mount. Extra water can be carried there as well, and those under-saddle mounts are widely available in two-cage models as well. If you used Zefal 1l Magnum bottles, that's an extra 2l capacity of...something, be it fuel or water. Depending on angle, the bottle could clear a rack-top load. Here's just one example:
http://www.sjscycles.co.uk/tacx-t6202-undersaddle-bracket-bottle-cage-prod18713/ Here's another using Andy Blance's preferred Profile bottle cages:
http://www.sjscycles.co.uk/profile-design-aqua-rear-mounted-double-bottle-cage-standard-prod20426/Just some thoughts from someone who has to carry huge masses of water more often than he wants to. Hope this helps in some way. Others will be along shortly with equally valid ideas that work well for them.
Best,
Dan.
EDIT: Have you seen the Bike Buddy bottle carriers? Here:
http://bikebuddy.co.uk/
