Last winter I converted my fatbike to tubeless. Since then I have ridden countless trips on them, I have set up a few more fat bike wheels tubeless, and I’ve learned a few things to make the process easier, faster, and is more reliable. I wanted to provide an update with my thoughts on running tubeless on a fatbike and the steps I use now.
I still opt for a simplified method of tape, valve stems, and sealant versus using split tubes and foam. I know others have success with those methods and I’m sure you will too if you decide to go that route. There is an excellent write up over on Riding Against The Grain for split tube fatbike tubeless setup if you decide to go that route. The good news is that we as a community have learned multiple repeatable methods for successful tubeless conversions.
I used Scotch Transparent Tough Duct Tape, Stans valve stems, Stans sealant, Surly Holly Rolling Darryls, Surly Knard 120 TPI for the rear, Surly Big Fat Larry 120 TPI for the front, Surly rim strips, Stans injector, air compressor, floor pump, and a five gallon bucket.
I used to recommend and use Gorilla Tape but I had two complaints with it. One, it is dreadfully heavy. When I removed the Gorilla Tape from a previous conversion I weighed it out of curiosity. I was shocked to see the Gorilla Tape from one wheel weighed .75 pounds. That’s 1.5 pounds worth of tape for a full conversion. No thanks. Two, I found that over time the Gorilla Tape broke down with exposure to liquids, this is a problem when liquid sealant is a key ingredient to the recipe. I set out looking for a replacement tape. I tried packing tape with some success. I read of others having success with clear duct tape so I decided to try it next. I set up my wheels in February with Scotch Transparent Tough Duct Tape and have had great success. If I’m completely honest, I had to add a few pumps of air every month or so, but I have to do that with all my tubeless setups. I’m a huge fan of how light this tape is, weighing in at .18 pounds per wheel for the tape. That’s over a pound less compared to Gorilla Tape with what seems like better resistance to liquids. I’m sold on it until Stans releases their own tape.
How I Did It:
One of the changes I do now is I always start with preforming a tire before trying to run it tubeless. With normal tires, I mount them on the wheel with a tube overnight to get the tire used to the shape and remove any folds in the beads of the tire. With a fatbike tire, I like to inflate a fatbike tube inside of the tire off of the rim. It tends to stretch out the tire making it easier to mount on a rim later.
I prep the rim by first cleaning everything. I next add a Surly rim strip. Another change I now incorporate with my fatbike tubeless conversion is that I no longer cut the tape after wrapping the left, right, and center sections. Instead, I run one continuous piece of tape from start to finish, thus removing edges where liquid can get underneath the tape and end your smiles. I start the tape at the edge of the rim, wrap the entire way around until you overlap the first pass by six or so inches, then I start transition the taping over to the center of the rim. I continue to wrap the tape around the rim until I again begin to overlap the center tape and then go six or so inches past that before transition the taping to the far side of the rim. I wrap this far edge with two full wraps of tape before transitioning back to wrap the center for a second time, and ending with wrapping the starting edge for the second time. By this point the left side, the center, and the right side have two full wraps of tape on them. I cut the tape for the only time after I have wrapped the wheel completely. I chose to double wrap because the tape is very light and I wanted the added security of no leaks.The wheel should look like this.
I use a pick tool heated up by a lighter to poke a hole through the valve stem hole to ensure no ripping of the tape as the heat makes a perfect cauterized hole.
I installed a tube into the tire, and mounted the tire to the rim as normally done.
I then inflated the tire to 30 PSI to ensure the bead seats on both sides of the wheel. Once the beads are seated I carefully deflated the tire and broke the seated tire free on only one side of the wheel, leaving the other side completely seated. I then remove the tube and installed the Stans valve stem.
I then remounted the open side of the tire to the wheel (it is most likely loose, and that is alright at this time).
I then wrapped the tube previously removed around the outside of the tire. This helps push the tire to the edge of the rim, helping seat the tire when you inflate it.
I then used an air compressor to inflate the tire. If you hear any air leaking out, press on that area with your hand. If you are having trouble inflating the tire, you can place it flat on a five gallon bucket with the open side down. This sometimes helps the tire seat.
Once the tire starts to inflate, I stopped inflating with the air compressor and switched to using a floor pump to inflate the tire to 30 PSI to ensure the bead was seated thoroughly. Once the bead is seated I carefully deflated the tire and removed the valve stem core. Using the Stans injector, I injected six ounces of Stans sealant into the wheel through the valve stem. I then re-inflated the tire with an air compressor initially. After the tire takes some air and begins to fill, I switched to inflating it with a floor pump to ensure I filled it to 30 PSI.
I then did the “Stans shake” to seal any leaks. If you don’t know what that is, there is a video detailing what I am referencing here.
After shaking the sealant onto the sidewall all the way around the wheel, I sat the wheel down on a bucket for about three minutes to allow the sealant to work its magic on the sidewalls of the tire.
I repeated the shake and bucket work at least three times per side of the wheel, rotating which side of the wheel is pointed down each time. You can spray soapy water on the wheel to check where your leaks are, and you will see some for a while. The leaks will eventually stop completely. If you are still seeing leaking sealant and or air, repeat the “Stans shaking” step until the leaks seal completely. It’s better to fix it here than deal with it on the trail.
I then deflated the tires to about 12 PSI (my desired riding PSI), and repeated the shake and bucket trick two more times to be sure everything was sealed all the way.
Everything works beautifully. The tires inflated to the beads with little effort this time and hold air completely. I believe that tires that have been set up tubeless in the past are much easier and more reliable to reset up tubeless. The Scotch Transparent Tough Duct Tape is much lighter than the previously used Gorilla Tape and proves to work well. I’m a fan. There is an obvious weight reduction, and you won’t have to worry about thorns or punctures. I think the tires shape is a bit more natural as there is no tube to dictate the shape and rolling resistance seems better as well. Oh and they still ride wheelies!