PDW Fatty Object – Bench Test


So I’ve been riding around with one of the New PDW Fatty Object CO2 inflator strapped to the seatpost of the bike I’m on, but up until now, hadn’t tested it out, because I only had one full CO2 canister and I didn’t want to waste it on a test. So I started to carry a pump along with the Fatty Object, ‘just in case’, while I waited for more 38g CO2 canisters. PDW sent me 3 more canisters and they told us that they’re going to offer replacement cartridges for sale on their webpage soon. PDW states that one canister will inflate a 26 x 4.8 up to 6-7 psi or add 20-22 psi to a 29 x 3.0 tire.

We conducted our test using a 26 x 2.4-2.75 Kenda Tube with a Surly Nate 26×4.0 and a Surly Bud 26×4.8 mounted to a set of Surly Marge Lite Rims. We removed the valve core on the tube and let all the air release, before re-installing the valve core and inflating the tire, using the Fatty Object. The inflator fits Presta or Schrader valves and very easy to get seated on the valve stem. You can control the amount of air that is released with an oversized control knob that’s simple to operate. The inflator had enough power to set the beads on the tires that we tested. To achieve the maximum transfer of pressure from the canister to the tire, we left the Fatty Object on the valve until we couldn’t hear any more gas transferring to the tire. This took a bit longer than I thought it would and during the inflation process, the entire Fatty Object apparatus frosts over and gets very cold. If you give it a good long minute to completely empty the canister, we think that you’ll be pleased with the outcome! One Canister inflated the Nate tire, that we tested, to 15 psi and as you’ll see in the video below, one canister inflated a 26 x 4.8 Bud to 7 psi, just like they said it would! I predict that you’ll see a lot of these strapped to fat-bike race rigs this winter.

The Fatty Object makes CO2 inflation a reality for fat-bikes and that begs the question, “Does this mean that I don’t need to bring a pump along any more?” I’ve had to walk out of the woods with a mechanical and it’s never any fun and in some environments, could become potentially hazardous, to one’s health and well being. So it’ll be interesting to see what all of you out there in Fat-Bike world think about how you’ll utilize this option into your bag of tricks. Will people racing the Arrowhead carry them? How would you use this new tool in your fat-bike lifestyle? (comment below)

The Tubes!

We did our bench testing with the tube(s) pictured above, but out in the field, I’m usually running tubeless. The blast of CO2 into a tubeless tire can cause the formation of big tire boogers. Seriously gross looking alien spiders from another galaxy, looking things. The control knob on the fatty object might be able to limit the release of gas to mitigate the formation of tire boogers, but that test will have to wait till we get a flat out on the trail. We have a couple more of these units out with our test pilots and their field testing is ongoing.

The bottom line is the PDW Fatty Object performed as advertised and I’m almost looking forward to my next flat, so I can try it out on the trail. For more information visit – ridepdw.com

About Gomez 2576 Articles
Just an old cat that rides bikes, herds pixels, ropes gnomes and sometimes writes stories. I love a good story.


  1. I carry a few co2 cans of different sizes and my pump as well. I have noticed that co2 doesn’t work that well in sub zero (C) temps. Maybe it has to do with the gas expansion?
    Good size can for the summer months though.

  2. Dreading the day I actually have to use my mini pump for a fatbike flat. Would be nice to have one of these, but so far I’ve always been lucky. Not too many thorns around, and apparently I only pinch-flat my CX bike.

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