How to mount tubeless tires without an air compressor

Yesterday I mounted those giant B fat 4.3” and 4.5” tires without an air compressor. I would’ve used an air compressor, but my crappy one broke, so I’m running what I brung.

Despite there being a million “how to seat your tubeless tires” videos I still feel like there isn’t a proper guide for folks that don’t have an air compressor. So without further ado, here’s my technique. It has a lot of [sometimes unnecessary] steps, but it usually works.

If you can, just try pumping up your tubeless tire with a floor pump or an Airshot and be on your way. (As an aside the Airshot is really the most underrated tool a home or traveling mechanic can have— get one!) If that doesn’t work you can pull the valve core to get more air flow, and try pumping or Airshotting again. This seems to always work with modern mountain bike rims and tires.

I find the above strategy doesn’t really work with fat tires or gravel/road tires, so when you have issues, or when you’re installing tires for the first time, read on.

1) Tape your wheels. I typically double wrap. On single wall fat rims (like the ones above) I put a couple more pieces of tape over the valve hole.

2) Inflate your tires with tubes, and leave it for at least an hour. I’ll often do it overnight, although it’s not completely necessary. This helps to push the tape down, and it seats your beads.

3) Deflate the tube and break just of the beads to pull out the tube. Do everything you can to keep one of the beads seated— it should be fine but some tires are a pain.

4) Install your tubeless valve.

5) At this point you can just try pumping it up with your floor pump, or hitting it with an Airshot. If that doesn’t work pull the valve core and try again. If that doesn’t work…

6) …pre-seat the bead using a tire lever (a la the Syd & Macky method). Then try your floor pump or Airshot again.

7) If step 6 doesn't work spray your tire bead with soapy water and try your floor pump or Airshot again.

8) Add your sealant through the valve using a sealant syringe. This won’t work with Stan’s Race sealant but works with most other sealants.

If you’ve failed, just go find an air compressor somewhere. You still might have to take the valve core out and hit it with soapy water. But I did all 8 steps above to get those giant volume fat tires installed without a compressor. I’ve had worse luck with lower volume tires in the past though, so good luck!