In the biking world there are a few topics that will provoke a massive discussion. Frame material and “definition of a gravel bike” are two of them, but today I want to talk about a third… tubeless tires. For years I’ve been hearing about the benefits of going tubeless, from lighter weight wheels, more suppleness, and lower psi. In particular in the fat bike world of winter ultras a lot of folks love to go tubeless so that they can get super squishy pressure for tackling rough snow. Since I just got my newest fat bike, and needed to swap on my studded tires, I decided to give it a go. Little did I know that attempting a fat bike for my first tubeless setup would be a bigger challenge than I had anticipated.

My journey began with a trip to the bike shop for materials: tape, sealant, injector, and stems. I decided to set up in my office, as my garage was particularly cold that day, and I knew this was going to be putzy. I got the wheels cleaned and began my taping job. Because fat bike rims are not solid, this was an interesting experience, as the tape wasn’t smooth (like it would be in a smaller rim). I managed to get two solid wraps of tape around the rims, poked small holes for the valve stems, and put the studded tires on. I had also purchased a quick inflator tool to help me seat the tires, however I quickly discovered that anything other an an air compressor was pointless when dealing with this much air volume.

With the tires mounted and ready for seating I headed over to the LBS for a quick inflation. My guy Bryan at Freewheel Roseville got them seated in about 10 seconds with the compressor and I was back on the road home, ready to start filling with sealant. I grabbed my injector and put in the full 6 oz that’s required for tires of this size. Immediately I started seeing little leaks on the inside of the rim, which meant that my taping job must not have been quite as good as I thought. The stem was also a big leak point and required tightening it down as hard as I could. At one point I also had to remove the valve core again to clean out all the gunk that had built up.

I got the tires mounted, inflated to 15 psi and let them sit in the garage overnight. The next day I went out for a test ride and within a quarter mile the back tire had gone flat. I hiked it back home, and thanks to the advice of some friends, filled it back up with air and started riding it more as a way to get the sealant to spread. A few days later I had both tires at a super squishy 5 psi and holding solid. Around this same time I bought a new portable bike pump and decided to try it out by upping the tire pressure to 8-9 psi (better for a mix of singletrack and road). The new pump worked great (thanks for the recommendation Paul!). Then the next morning, my front tire was flat as a pancake. It appears that in pumping up the tires I had messed up the seal around the valve stem and it was now leaking a lot.

I couldn’t get the stem to seat right again, and that left me with needing to take the tire off again to see if I could fix it on the inside. I don’t have an air compressor at home so the idea of needing to bring it back in to the shop to get it seated was unappealing. I decided to call the experiment over for the front wheel and proceeded to remove the sealant, clean off the inside of the tire a bit, and go back to a tube. So far the back wheel is holding strong, so I’ll avoid swapping that out until I absolutely have to. For now I’ve found a good sweet spot around 8 psi in the front and 9 psi in the back which works well for the mix of riding I’m doing around town. The back wheel is lighter and more supple, but not so much more that it bugs me. It’s only on rare occasions that I’ll feel a difference, and given that I’m riding on a lot of snowy, crappy roads, and icy paths, I’m just lucky to stay upright. I’ll worry about feel when I’m spending a lot more time on groomed singletrack.

Am I happy I gave this a try? Absolutely, 100% yes. In fact, having gone through this convinced me that I want to convert my non-winter daily driver (Salsa Vaya) over to tubeless come spring. Having gone through this experience I know I’ll be able to fix some of the things I did wrong this time.

So what did I learn?

• Fat bike tubeless is harder than you think it would be. Usually fat bike tires are easier to work with, but not in this case.
• Never underestimate the power of a good taping job. Take your time and do it right.
• Air compressors are not optional for fat bike tubeless setups. I might be able to get by without one for my 700c tires, but having one would make that job a lot easier.
• Be prepared to deal with a few short rides close to home to ensure everything is sealed. Don’t go further than you’re willing to walk back.
• Have a good portable pump. The Topeak Mini Morph is awesome and I’ll take a closer look at that one in a future review.
• Don’t use old tires. The studded tires I have are 3-4 years old. They’ve been seated and sealed multiple times before I ever got them (bought them used). I know that affected my ability to get a good seal, and made the job harder than it needed to be.

This was a great experiment, and I learned so much. I’m building up my cadre of bike skills, and feel more able to take adventurous steps into new areas I had never considered before. For that experience, I’m really happy with how this turned out. Now I can’t wait until spring to try again, but first, I think it’s time to hit a hardware store for an air compressor… wonder if that will fit on my rack…