MSR Trailshot Review: Hell or No Water

MSR recently released the Trailshot, a new type of water filter that employs a one-handed squeeze operation in a pocket-size and lightweight package. We took it on a month long tropical adventure through Cuba to see if it would meet the needs of two thirsty cyclists…

Planning for potable and bacteria free water on a big overseas trip usually requires a bit of foresight — thinking through what types of critters you need to avoid, how much water you’ll require, and from where it’ll be sourced. Prior to this trip we didn’t give it much thought. From what we could gather, there hadn’t been much two-wheeled exploration of Cuba’s forgotten horse tracks, remote dirt roads, and dusty backwaters. Intel was limited and we had no idea where we’d find water, nor how often. On relatively similar trips in Africa we brought both the Sawyer Squeeze filter as well as a rechargeable Steripen — the idea was to filter particulates and bacteria, then zap viruses and other microscopic organisms that the 0.2 micron Sawyer filter couldn’t remove. For Cuba we threw caution to the wind. MSR sent us their then yet to be released TrailShot and we tossed it in a bag with very little information and no backup… come hell or no water.

MSR Trailshot Review, ultralight water filter
  • MSR Trailshot Review, ultralight water filter
  • MSR Trailshot Review, ultralight water filter

Over the last couple of years MSR has invested considerable R&D in portable water purification. In 2016 they launched a couple of game changers including their highly touted Guardian Water Purifier — winner of several awards and considered exemplary for international travel due to its self-cleaning design and the fact that it removes viruses in addition to microscopic organisms. However, the Guardian weighs about 482g (1lb 1oz) and costs about $350. Maybe not the ideal solution for ultralight bikepacking. Enter the MSR TrailShot. While it can’t handle viruses the small and lightweight TrailShot uses similar hollow fiber filter technology as the Guardian and is suitable for removing bacteria, protozoa and particulates from almost any moving water source — MSR advises against filtering from stagnant water. And, it does all this at a fraction of the size and cost of the Guardian. The TrailShot weighs about 153g (5.4oz) and retails for a hair under $50. The MSR TrailShot also comes in a tidy package. Bearing the abstract resemblance of a pregnant hand grenade, it is about the size of a large bar of soap or a small sweet potato. It’s worth noting that the MSR TrailShot filters down to 0.2 microns, while the Guardian filters down to 0.02 microns.

MSR Trailshot Review, ultralight water filter
  • MSR Trailshot Review, ultralight water filter
  • MSR Trailshot Review, ultralight water filter
MSR Trailshot Review, ultralight water filter

Prior to leaving for ‘the pearl of the Antilles’, I had actually tried the MSR TrailShot on a couple of overnighter trips, so I knew that it was uncomplicated to use and fast working. You simply plunk the hose into a stream, give it a few gentle priming squeezes, and then pump directly into a bottle, bladder, or drink straight from the conical spigot. MSR claims it filters one liter of water per minute. While I didn’t set a timer, I was initially amazed by its speed of operation; I would have guessed that it filtered two liters in a minute. I knew from the first use that it was perfect for weekend mountain getaways in the States. What I didn’t know is how well it would fare over the long haul, when tasked with providing clean water for two people from what would most likely be highly questionable sources.

On this particular trip we pumped directly from flowing rivers, clear mountain streams, murky trickles, and agricultural runs. Some of the water sources contained sediment, but generally speaking they were mostly clear. We also filtered tap water, which involved using a pot or bowl to capture the water before pumping it into our bottles. On average, Gin and I consumed about 6-8 liters per day. So over a 21 day ride and another week in the country, I would guess that we filtered 150-160 liters of water. Considering that MSR claims the replaceable filter cartridge is good for 2,000 liters, we barely scratched the surface.

MSR Trailshot Water Filter Review

That said, such heavy use of the MSR TrailShot didn’t come without issues. After a few days in the Sierra Maestra the flow rate started to slow considerably. The fact that I never read the instructions is partly to blame. Later I learned that backflushing the TrailShot involves giving it a few hearty shakes. This certainly helped, but it never seemed to have the virulent flow that it did out of the box. However, upon return I learned that these ‘shakes’ should be a little more significant than gentle joggles. So after a few extra sturdy shakes the TrailShot is back to a steady flow, albeit still not as great as it was out of the box.

  • Weight 153 grams (5.4 oz)
  • Flow Rate 1 liter per minute
  • Filter life 2,000 liters (filter is replaceable)
  • Removes Bacteria (99.9999%), protozoa (99.9%), and particulates
  • Price $49
  • Dimensions 5 x 2.5 x 2″ (15.25 x 6.1 x 5.1cm)
  • Place of manufacture USA
  • Contact

Wrap Up

With an emphasis on trail running and mountain biking in their marketing, MSR made it obvious that the new Trailshot pocket-sized water filter was designed for quick and active adventures. So it was no surprise that the MSR TrailShot is also ideal for weekend and overnight backcountry bikepacking trips. Given its size, weight, and price, the TrailShot seems like the perfect system for jaunts where there are plenty of water sources to dip into. Upon first use it was clear that this product is a winner for such exploits.

So how does it fare when pitted against longer bikepacking trips? With a route such as our trans-Cuba where the hydration requirements were high and the water sources are variable, the TrailShot was adequate. As mentioned, the flow rate was reduced to a trickle at some point, albeit partially due to ignorance on our part. But this was since rectified and the TrailShot continued to provide good pure water. Suffice to say, we never got sick… which is a worthy mention as Cuba’s water is notorious for Turista and even dysentery. In hind site, I probably would have included a rechargeable Steripen in the kit to take up some of the tap water duties. It’s also worth noting that I’ve heard equally good reports when using the Trailshot on pre-strained turbid desert water.


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