As bike travelers we have an innate drive to explore the path less traveled, be it a remote backcountry trail or the backroads of a foreign land.
We also have this pesky need to drink water pretty often, or we die. And most of us don’t enjoy emergency pooping behind a bush on the side of a busy road due to digestive issues.
Thus it’s no surprise that pedal-powered explorers want to know: what’s the best water filter for bikepacking?
There’s no one-size-fits-all answer, unfortunately. The best water filter for bikepacking in the US backcountry will be different from the best water purifier for bicycle touring in Nepal.
After pedaling thousands of miles on five different continents, you can bet I’ve experimented with a bunch of options, and researched even more! In this article I’ll explain what to consider when looking for a bikepacking water filter, and how to choose between the many good ones out there.
Nasty Waterborne Pathogens
First, let’s quickly review the types of little buggers we’re trying to protect ourselves from.
In this table I’ll use the common but somewhat flawed terms “developed” and “developing” countries. What I really mean by “developed” is “countries where the sanitation infrastructure is developed enough to keep pathogens carried in human waste out of the water supply.” The US and much of western Europe fall into this category, as do a number of other countries.
On small screens, this table scrolls left and right.
|Bacteria||Parasites / Protozoa||Viruses|
|Examples||E. Coli, Salmonella, Cholera||Giardia, Cryptosporidium||Hepatitis A, Norovirus, Polio|
|Size||0.2 – 5 microns||1 – 15 microns (relatively big)||0.02 – 0.3 microns (relatively small)|
|Removed by filters?||Yes||Yes||Not usually|
|Removed by purifiers?||Yes||Yes||Yes|
|Killed by chemical treatments?||Yes||Not always||Yes|
|Found in water in developed countries?||Tap water: no|
Natural water: sometimes
|Tap water: no|
Natural water: sometimes
|Tap water: no|
Natural water: rarely
|Found in water in developing countries?||Tap water: sometimes |
Natural water: sometimes
|Tap water: sometimes |
Natural water: sometimes
|Tap water: sometimes |
Natural water: sometimes
The most common problem caused by all of these: diarrhea and other digestive upset, ranging from mild to catastrophic. In rare cases, viruses can be fatal (for example, Polio is still a problem in some parts of the world) though travel immunizations offer protection.
How do these buggers get into the water? Usually through the poop of infected people or animals. In the US, cattle and human campers (both of which poop in the woods) are common causes of contamination even in remote areas. Unless you know for sure that no one and nothing has been pooping upstream, you should treat your water!
Purifiers versus Filters
Many people think a water purifier and water filter are the same thing, but there is an important difference!
Filtration strains out bacteria and parasites, but viruses are so small that they often slip through. People use filters for treating natural water sources (streams, lakes, etc.) in developed areas where viruses are usually not an issue.
I know many readers are US-based bikepackers, so to save you time: for bikepacking in the US, a filter works fine. Yes, even for those nasty cattle troughs in the southwest. This assumes you’ll fill up with tap water in populated areas where it’s easy to get and surface water could be more contaminated.
Filters are also a great choice for bike travel in countries where it’s generally safe to drink the tap water. In most of these places, as in the US, I would filter all water from natural sources but not worry about using a purifier. In places where locals drink the tap water but unfamiliar bacteria can cause problems for visitors, I would filter tap water too.
Purification removes bacteria and parasites like filtration, and also neutralizes viruses. Purifiers (or other purifying methods like chemical or UV treatment) are necessary for treating natural water and often also tap water in developing areas. Though some bike travelers rely on bottled water in these places, a purifier will give you more flexibility, reduce plastic waste, and save you money in the long run.
If you travel a lot, a purifier is likely the best choice. On my bike tours in Southeast Asia and northern Africa, for example, I purified my drinking water from both natural sources and the tap.
You might also want a purifier if you’re drinking surface water in populated areas of developed countries, but I don’t know why you’d be doing that instead of just filling up with readily available tap water.
Water Filters for Bikepacking
For bikepacking in the backcountry of the US, western Europe, or other countries with safe drinking water, a water filter is all you need. They last a long time, remove dirt and other nasty stuff that chemical treatments don’t, and make your water safe to drink in areas where viruses aren’t a concern.
Below are some of the best water filters for bikepacking. All three of these use hollow fiber filtration technology, but package it in slightly different ways.
The Sawyer Squeeze (and its variations) might well be the most popular water filter among backpackers and bikepackers, and for good reason. I’ve been using it for years with great results and think it’s an excellent water filter for bikepacking.
There are three models of Sawyer filter: the original Squeeze, the smaller Mini, and the smallest Micro. Flow rate decreases with size and clogging becomes more likely. For especially dirty water sources like those common in the American Southwest, I recommend the largest Squeeze model to avoid clogging. For clear mountain streams and lightweight bikepacking setups, the Mini or Micro would work well. All models need to be backflushed periodically (easy to do) to keep them flowing well.
All the Sawyer filters have a flexible setup. Use with a squeeze bag (though I highly recommend replacing the included pouch with a CNOC bag), attach to a hydration bladder hose with a connector kit (either for filtering into the bladder, or in-line filtering as you drink), or set up as a gravity filter with a CNOC dirty bag.
Best for: individuals, or groups if used with a CNOC bag as a gravity filter.
It’s cleaned by swishing instead of backflushing, which is easier but also less effective if the filter gets clogged. I’ve heard the flow rate decreases significantly with use. On the plus side the filter itself is very compact.
Best for: individuals or groups.
If you’re riding in a group and want the most convenient solution, the Platypus GravityWorks filters 4 liters of water at a time. It’s a bit bulkier because it includes its own clean bag instead of integrating with your bottle or hydration bladder. It’s also more expensive. But I’ve found the flow rate is good, it’s easy to backflush, and it doesn’t clog easily, making it a very convenient solution.
Best for: groups
Gravity versus Squeeze Filters
This is a matter of what pushes the water through the filter: gravity, or you. All these filters can be considered “squeeze” or “gravity,” depending on how you configure them and whether you hang them up on a tree (or your handlebars) or squeeze the bag.
I prefer the convenience of a gravity water filter for bikepacking so I can do other things – setup camp, eat lunch, etc. – while my water filters itself. But if you’re only filtering a liter or two at a time and packing really light, you might prefer the weight savings and compactness of a more minimal squeeze pouch.
Drawbacks of Hollow Fiber Filters
All three of these water filters – Sawyer, Katadyn, and Platypus – use hollow fiber technology. These types of filters are easily damaged by freezing or impact, so you’ll need to take good care of them.
If there’s any chance the temperature is near freezing, carry the filter cartridge in your pocket and sleep with it at night. Protect them from hard impacts too. If you think there’s a chance the filter is compromised, you shouldn’t use it. It’s surprisingly easy for this to happen, so have a backup plan like chlorine dioxide drops or sharing a friend’s filter.
Hollow fiber filters gradually clog over time, and no amount of backflushing or swishing will return them to their original flow rate. If you bikepack a lot you can expect to replace your filter cartridge from time to time.
Other Types of Filters
Hollow fiber squeeze/gravity filters are popular for many good reasons: small size, light weight, flexible setup, and ease of use.
Here are two other types of filters that I don’t recommend for bikepacking.
Pump filters: These classics, like the MSR Miniworks, used to be popular before hollow fiber filters were developed. Unless you’d like to balance your bikepacking with an upper body workout from all that pumping, I don’t recommend them for most bikepackers.
Straw filters: There are a number of personal water filters, straw filters, and water bottle attachments that don’t integrate well with the types of water carrying systems we use while bikepacking. Unless you want to limit yourself to using only compatible bottles, or only drink from water sources while you’re at them, I don’t recommend these types of water filters for bikepacking.
Chemical Water Treatments
Chemical water treatments like chlorine and iodine have their own special pros and cons. They do kill viruses, but they don’t kill Cryptosporidium, a large hard-shelled parasite found even in the US (though rarely). Though many backpackers and bikepackers do use them, you run a small risk of getting sick from Crypto if you do.
Chemical treatments are also not ideal for long-term bike travel. They run out, obviously, and some people worry about the health impacts of using them regularly.
Another drawback of chemical water treatments: they don’t filter out dirt, larvae, dead bugs, and all the other fun stuff you find in less pristine sources. A cloth filter helps but your water will still be cloudy and taste nasty. It may not make you sick, but it’s not pleasant to drink.
Chlorine dioxide is, in my opinion, the only chemical water treatment worth using. It kills all bacteria, viruses, and parasites, but only if you wait four hours for it to get through Cryptosporidium’s hard shell (everything else should be neutralized within 30 minutes).
Popular chlorine dioxide products include:
- Aquamira drops: best for when you treat variable amounts of water, because you can adjust the number of drops to match the container volume.
- Potable aqua tablets: one tablet treats one liter, so these are best for when you always treat water in increments of a liter.
- Katadyn Micropur tablets: another popular chlorine dioxide tablet, similar to Potable Aqua
Here are three good use cases for chlorine dioxide:
- Short, fast, and/or light trips: If your water sources are fairly clear and you don’t think Crypto is a risk (true in most remote areas of the US), chlorine dioxide is a convenient and lightweight option. I use it for short bikepack races like Smoke ‘n Fire 400, where I’ll occasionally need to fill up from a clear stream but otherwise get my water from restaurants and gas stations.
- Combined with a water filter when biking overseas. Together this combination acts as a purifier by filtering out bacteria and parasites (including Crypto) and also neutralizing smaller viruses. This works well if you already have a filter and don’t want to buy new gear for a short trip overseas.
- As a lightweight backup in case your primary filter is lost, or damaged by dropping or freezing.
Water Purifiers for Bike Travel
If you plan to log miles abroad in a variety of places, you’ll need more than just a filter. A purification system will remove harmful viruses that filters miss.
Purifiers are less common than filters, more expensive, and generally heavier and bulkier. They have more work to do, so this makes sense. If you don’t actually need a purifier for the areas you’ll be riding in, one of the filters listed above makes more sense.
Be sure to read carefully to make sure your purifier choice actually removes bacteria, parasites / protozoa, and viruses. Beware, I have seen filters incorrectly labeled on Amazon as “purifiers.”
Lifestraw Mission Gravity Purifier
The Lifestraw Mission is a high volume gravity setup similar to the Platypus GravityWorks, but it purifies instead of just filtering. Most bicycle travelers will want the 5 liter bag, but it even comes with a 12 liter option.
Best for: groups
SteriPen UV Water Purifier
The SteriPen is a unique solution that uses UV light to purify water. It comes in several different models suited to slightly different use cases, but all will purify water as long as it’s not too cloudy.
With cloudy water UV light doesn’t kill pathogens as effectively, so you could get sick in addition to drinking dirt and other harmless particulates. So pre-filter cloudy water before using UV treatment, both for taste and safety.
Pros: Quick and easy to use, compact.
Cons: Requires a container of the right size and shape. As an electronic device it can fail or run out of battery (I suggest chlorine dioxide as a backup). Doesn’t work if water isn’t clear.
Best for: individuals or small groups
The GRAYL water purifier uses a hard-sided bottle and a pressing action to force water through the cartridge. If you have a good way to carry the hard sided bottle on your bike, it’s not a bad way to go. It can become hard to press and clog over time with dirty water, but if you’re looking for a personal-sized water purification system that doesn’t depend on electronics it’s one of the few options available.
Best for: individuals or small groups
Filter + Chlorine Dioxide
Here’s a creative option ideal for those who already have a filter and don’t want to buy a purifier for a short trip overseas.
Chlorine dioxide kills bacteria, viruses, and parasites except Crytosporidium. The filters listed above strain out bacteria and parasites (including Cryptosporidium) but not viruses. Combine them and you’ve got a flexible and relatively low-cost purification system.
First, filter the water into whatever container you’ll carry it in. Then, add the right amount of chlorine dioxide drops based on the volume, wait 30 minutes, and you’re good to go!
Best for: individuals or small groups, short trips (otherwise you’ll need a lot of chlorine dioxide)
Obviously most bikepackers aren’t going to boil water as a primary method of purification. It’s inconvenient, uses fuel, and leaves us with hot water that needs to cool. But I include it here as a reminder for emergencies.
If you’re ever stuck without another method, boiling is an effective purification method that kills bacteria, parasites, and viruses. Bring water to a rolling boil for a few seconds to make sure all water has reached boiling temperature, then let it cool.
Other Water Contaminants
Other than bacteria, parasites, and viruses, here are a few other contaminants you may need to consider in special cases.
Toxic algae: A growing concern in parts of the United States, cyanobacteria (blue-green algae) produces cyanotoxins that are released into the water when the spores rupture. These toxins can be fatal. Though filters remove the spores themselves, they don’t remove toxins that have already been released into the water. Purification methods like boiling, chemical treatment, and UV light don’t either. An activated carbon filter within a purifier, or added as a second step after filtration, seems to be the only way to remove some but not all of these toxins.
Heavy metals: In areas with a history of mining, surface water in creeks and lakes can contain unhealthy concentrations of heavy metals. I’ve encountered a few places in Colorado, for example, where locals warned me not to drink from the streams. Activated carbon filters are the best defense against heavy metals, or you can just plan ahead to avoid filling up in these areas.
Microplastics: I’m honestly not clear on how common these tiny pieces of plastic are in natural water sources, or whether they’re a problem. But since the smallest microplastics are around 2 microns (1.6 according to Wikipedia) which is larger than many bacteria, any standard water filter should filter them out.
My Personal Picks
I’ve listed a lot of options here, and they all have their own advantages. It can be hard to choose!
For those in search of a quick answer, here are the water treatment systems I personally use for bikepacking and bicycle travel.
Sawyer Squeeze Filter: My recommended water filter for bikepacking trips in developed places like the American southwest, such as Arizona and New Mexico, where you’ll be drinking from very dirty sources. I choose the Squeeze over the smaller Mini or Micro models in this case because it doesn’t clog as easily. Examples: GDMBR (especially New Mexico), Arizona Trail.
Sawyer Mini Filter: My recommended filter for mountains or anywhere in developed countries where water is likely to be clear. I choose the Mini over the Micro because it’s not much heavier and seems less likely to clog over time. Examples: Colorado Trail, GDMBR (from Colorado north), Carretera Austral in southern Chile and Argentina.
Aquamira Chlorine Dioxide drops: My recommended treatment for short, fast, and light rides (like bikepacking races) in developed areas with mostly clear water. Examples: Smoke ‘n Fire 400, The Big Lonely.
Sawyer Squeeze + Aquamira Drops: My recommended purification method for solo international trips in developing areas. Examples: Sudan, Southeast Asia. For a long trip with a partner or group I would be tempted by the Lifestraw Mission gravity filter with a 5 liter bag.
When choosing a water filter for bikepacking or touring, here are some other aspects to think about:
Variety of water sources: Bikepackers cover ground faster than hikers and therefore might drink from a wider variety of sources. For a route like the GDMBR we need a system that works when drinking from a clear mountain stream, a cattle trough in the middle of the desert, and the dodgy-looking garden hose behind the saloon. And that’s just in the US! Those traveling internationally have even more to deal with.
Large amounts of water: In hot or dry climates, bikepackers often carry 6 or more liters at a time. Choose a treatment method that’s fast, won’t run out like chemical treatment, and won’t drive you crazy like pumping or squeezing. Gravity setups are great for this case. (For help deciding how much water you need, see How Much Water to Carry While Bikepacking?)
Multiple water containers: As cyclists we often use multiple water containers of different shapes and sizes. When you choose a water filter, consider how it will interface with the hydration bladder in your frame bag, bottles in your cages, that Gatorade bottle you saved from the gas station for a long dry section, or whatever. Systems that only treat a small amount of water in a specific container can be inconvenient. (For help fitting all these containers on your bike, see 9 Ways to Carry Water on a Bike.)
Flexible water capacity: On a long ride it’s common to have a few sections that are much drier than others, so it’s nice to have expandable water capacity. This might mean buying extra disposable bottles or carrying a collapsible bottle or bladder. A nice advantage of gravity filters is that the dirty bag can be used as extra water capacity when needed.
Hard-to-fill-from sources: Ever tried to fill up a filter bag from a slow trickle or shallow puddle? Containers with wide openings make this easier, or you can use a cup or pot as a scoop. For the tiniest of trickles, try engineering a leaf spout to create a dripping faucet.
Weight and style of travel: Gear weight and size matter more to some folks than others. Consider how much you value saving weight, time, energy, and money as you choose your water treatment method. Usually you can only optimize a couple of those aspects at a time.
Backup methods: Filters can easily break, freeze, or get lost. I’ve even had chlorine dioxide bottles crack and spill! You can roll the dice and drink untreated water in an emergency and deal with the consequences later, but it might be unpleasant or even dangerous. I think chlorine dioxide makes a great lightweight backup option to get you to civilization if needed.
More Bike Travel Resources
If you’re choosing a water filter for bikepacking or bike travel, you might also like these:
- Bikepacking 101: A Beginner’s Guide
- What to Pack in Your Bike Travel Repair Kit
- Riding Chile’s Rugged and Beautiful Carretera Austral
For even more pedal-powered goodness, visit the bike travel resource center. Happy trails!
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