Not long ago, an email arrived in our box from Jonathan, who is planning a bike trip through Western Africa.

He’d read our thoughts on water treatment options for remote bike touring and wondered if we’d ever tried a water bottle with a filter built into the cap? Options include the Clear2Go Filter Water Bottle and the Travel Tap (retails for about $50 U.S.).

The idea behind these water filters is that water is made safe to drink by pushing it through a filter in the top of the bottle. We’ve never tried these filters, but here are a few of our thoughts.

The upsides we see are:

• Lightweight: no need to buy and carry a separate water filter.
• Relatively inexpensive. TravelTap filters are advertised as good for 1,600 litres of water or about 3 cents per litre. To compare, the MSR Miniworks EX costs about 4.5 cents per litre.
• Doesn’t require batteries.

Our concerns are:

• The method: squeezing water through a bottle top could be a relatively difficult way to filter large quantities of water. The TravelTap, for example, advertises a filtration rate of about 300ml of water a minute, compared to up to 1 litre a minute for the MSR Miniworks EX. Sometimes, when filtering a lot of water, we even found the MSR filter a bit tedious. We can’t imagine something that goes a third of the speed! (See our MSR Miniworks EX review)
• Once you start using your bottle for water filtration, you can’t drink straight out of the mouth of the bottle, or you’ll risk being exposed to contaminated water.
• You won’t be able to put anything other than water in the bottle, like juice.
• Spare filters could be difficult to source on a long tour.
• If the bottle breaks, will you be able to find another water bottle the same size to attach the filter to?

Peter Gostelow initially carried a Travel Tap on his Big Africa Cycle, but found it difficult to squeeze the water through the bottle. He recently sent it back home.

“For the last 2 weeks i have been drinking water from pumps, at least in the countryside. In towns and cities it is easy to buy water in bags at very low cost, which is usually chilled. I have purifying tablets if I really need to use them,” he told us.

We can see these types of products potentially being useful for shorter bike tours, where you won’t need to filter water day after day, and probably not in great quantities.

On longer expeditions, however, we would favour something with a higher flow rate when filtering. We also like the flexibility of being able to put things like juice in our bottles occasionally, and drinking straight from the mouth of the bottle when we’re really thirsty.

What do you think? Have you used water bottles with built-in filters before? Tell us your experience by leaving a comment.