Not long ago, someone discovered that cycling water bottles (or bidons) contained a toxic chemical called BPA that was potentially seriously harmful to human health. Some, though not all, bidons are BPA-free, but even if they are, it doesn’t stop them making your drink taste all nasty and plasticky nor providing an excellent long term breeding ground for all manner of unpalatable, and possibly unhealthful, fungi and bacteria. This latter problem is particularly bad if you fill a bidon with anything other than water, particularly sugary drinks. I don’t expect milk is much good either.
Cyclists who return home after a ride can wash out, or even boil their bidons to keep them tasting fresh. For touring cyclists this is more difficult. And that’s one of the reasons I really like the Topeak Modula XL water bottle cage. It is designed not for cycling bidons but for your standard-issue mineral water bottle. This is the kind that doesn’t taste of plastic and that can be easily recycled & inexpensively replaced if it starts to get a bit whiffy.
More than that, mineral water bottles are bigger than normal cycling bidons, which makes them ideal when you’re wild camping as it’s always nice to have a plentiful supply of water for cooking, making tea, brushing your teeth and all that kind of thing.
The bottle cage is vertically adjustable so it will take a variety of different types of water bottle. I’d recommend using sparking water bottles as they tend to be more durable than most still water bottles which are a bit flimsy.I’ve used one for years, though there are reports of the cages breaking when ridden over rough ground. Being aluminium, they’re lightweight but difficult to repair. Maybe someone will come out with a steel version.
Another approach is only to use bottles up to a litre in capacity, so as to reduce the strain on the cage, or not to put more than a litre of water into the bottle unless you absolutely need it. For cycle tourists heading to really dry, rough or remote places, it’s worth considering taking a water bag to supplement a frame-mounted bottle for drinking while riding.
I really like stainless steel waterbottles. They’re super durable and don’t have any nasty plastic coatings. They’re easier to find than ever, and cheaper too. But I’ve never found a way of keeping a metal water bottle securely fastened in a frame-mounted bottle cage. Maybe a leather or neoprene wrapper would help. Any suggestions?