Summer hydration. The ridiculous and the practical.

I have read that you should drink around 500ml (16oz in American) of water per hour, when riding a bicycle. From my experience this is hugely temperature-dependant, and probably only accurate for riding with moderate vigour between 25c-30c (77f-86f). Touring in Iceland two years ago I made it through an entire day of riding (in the rain, at around 3c/37f) on 1.6l (54oz)of water. I wouldn’t recommend this, but we didn’t find any fresh water that day. I am currently in Arizona, it is summer and the temperature on my commute to work is between 35-45c (95f-113f). My hydration needs are about double the above recommendation, and I seem to need more than 500ml for a 30-40 minute ride.

Last year—riding the Sunset Limited—I carried 5.5l (186oz) of water each day, to make sure I would not run out during the ride. Temperatures on that ride averaged in the upper 20s, maxing around 36c. To carry this amount of water, I had a 2l Platypus Hoser reservoir in a (Revelate medium Tangle) frame bag, a 1l collapsible bottle up front, one conventional bidon and two Nalgene 1l (34oz) bottles.

On my new Surly Midnight Special I am now rocking a Cranktank4 which holds 4l (135oz) directly above the bottom bracket, and a 1l Nalgene below the bottom bracket, so I have 5l (169oz) sitting in the centre of the bike.

I have been testing the Cranktank4 commuting (since it is still too hot for a long ride). The tank is really well designed and made. The insulated hose is strapped to the frame with a piece of Velcro, and has a quick-disconnect at the lid. The tank itself is held on with two Velcro straps, which is both easy and fast to put on and take off for filling (and yes, you can add water to it without taking it off the bike). Drinking from a hydration hose whilst riding is much easier than using a bidon: I find that I often need multiple tiny sips to avoid a weird feeling of breathlessness which seems to be some inefficient stupidity on my part, where I can’t time swallowing and breathing correctly, which often results in inhaling water or burping. Drinking from a hose helps because I can keep the valve in my mouth for a few breaths, taking smaller sips than I instinctively want to take when holding a bidon and turning to the side to take in water.

How does weight come into things when carrying 4kg (141 of the other kind of ounce) of water, you ask?

Well, apart from the logistical difficulty of fitting 4+ litres of water on a bicycle, using a single reservoir is actually pretty efficient, weight-wise. As I have previously noted, the Velo Orange Mojave cage weighs around 150g (5.3oz), a Nalgene is around 170g (6oz), so carrying 4l would weigh about 5.3kg (187oz), and be hard to fit on my frame as I don’t have triple-bosses on my forks. My Cranktank4 (without its hose) weighs 407g (14.4oz), so 4l weighs 4.4kg (155oz) which is a significant weight saving.

Now, just to clarify how practical the Cranktank is, I have fitted 4.13l (140oz of the previous kind of ounce) capacity to my singlespeed rat-rod commuter in a manner that Bicyclepubes and a few others would approve of.

Now you want to know how much this pile of crap weighs, right? The 4 conventional bidons and 3 Polar bottles alone weigh 750g (26.5oz of the weighty kind)!

To do this in a more clean and less-ziptied manner, a Specialized Purist bidon and a KingCage stainless cage weigh 128g (4.5oz), so if you could find the space on a bike to fit 8 conventional bottles and cages, this would weigh about 4.5kg (159oz).

Carrying 4l of water on your bicycle with the best conventional bottles and cages would weigh about 100g (3.5oz) more than the Cranktank4, and your bicycle would have no space at all to carry anything else, so bikepacking would be difficult without a full sized hiking backpack, which I most certainly would not recommend cycling with, as it would probably cause you permanent injuries after more than a couple of miles.

One final note: I am not sponsored by Adventure Hydration, I am just incredibly excited by the Cranktank4, as it fulfils a task better than any other solution I have seen. With two largely-unused degrees in industrial design, I find it hard to fault the product, hence the praise.