Angelos Orfanakos

Tubeless tire conversion on a mountain bike

Background

When I started mountain biking, my friends (who are more experienced) suggested that I should convert my wheels to “tubeless”, i.e. removing the tube and adding sealant for plugging small punctures. It was something totally unfamiliar to me and sounded too involved. I reasoned that it’s unnecessary since I hadn’t had a flat by then.

Fast forward a few rides and I do get a flat with 3 pairs of 2 small holes on the tube at the same time. After wasting 2 hours trying to replace the tube, pinching the new tube and breaking 2-3 tire levers in the process due to a super-tight tire-rim fit (granted, I hadn’t replaced a tube before — now it only takes me 10 minutes), I decided it was time to “go tubeless”

This post documents almost everything I’ve learned while going through the process and I hope it saves you some time. It is what I wish I had when I started out.

Pros

Cons

What you will need

Note: Some bikes (mine included) have different front and rear rim widths, so it is important to check your rim dimensions before buying tape, valves and tires.

Instructions

  1. Remove the wheels from the bike. Watch this, this and this.
  2. Remove the tires and the tubes from the wheels, using tire levers as necessary, taking care not to pinch a hole in the tube. Keep the tubes as spares.
  3. Remove any existing tape from the rims, using a knife to raise it. Keep it as spare.
  4. Clean the rims thoroughly with a soft rag and rubbing alcohol
  5. Tape the rims to create an airtight seal, starting opposite of the valve, overlapping the tape by 10 cm at the end, and trying to have as few air bubbles as possible
  6. Insert a toothpick in the center of the valve hole from below and push gently up until it touches the tape
  7. Use a knife to make a very small round hole where the toothpick is and then remove the toothpick
  8. Insert the valve in the hole, gently pushing it down until it sits firmly on the rim channel (this will cause the tape hole to grow)
  9. Use a tire lever to push down the valve with force and screw the nut tightly on the valve with your hand (do not use a tool)
  10. Install one bead of the tire and seat it on the rim channel, using tire levers as necessary
  11. Install the other bead of the tire, using tire levers as necessary
  12. Pour dish soap in a bucket with water and shake with your hand vigorously to create a lot of foam
  13. Use a soft brush to pick the foam (only the foam, not water!) and briefly brush the tire sidewalls, both sides (some foam will enter the rim — that’s OK)
  14. Using a floor pump, quickly pump the tire to 50 psi (or lower if this exceeds your tire’s or rim’s maximum pressure). This will cause the tire beads to lock onto the rim sidewalls (you will hear loud popping sounds)
  15. Check the wheel for any leaks by listening closely for escaping air or, better, immerse the wheel in a bathtub with water and look for air bubbles
  16. Assumming the wheel does not leak air (if it does, consult the Troubleshooting section), deflate the tire
  17. Remove the valve core with a valve core tool
  18. Pour the sealant liquid into the valve hole (check the recommended amount on the back of the sealant bottle based on your tire width)
  19. Screw the valve core firmly (but not too much) with a valve core tool
  20. Pump the tire back to 50 psi (or lower if this exceeds your tire’s or rim’s maximum pressure) and shake the tire on a horizontal plane with big wave-like, round motions and also rotate it on a vertical plane to give the sealant a chance to cover any small holes
  21. Leave the wheel horizontally for a while and repeat the shaking process every few hours
  22. If you know the tire has holes (if it’s used, it has), you can try to leave the wheel vertically so that the holes are at the bottom. This will give the sealant a chance to plug them more effectively. Rotate the wheel slightly from time to time to cover the whole tire surface.
  23. Wait one day and then deflate the tire to your ideal pressure
  24. Wait one more day and then check the tire pressure with a pump to make sure it hasn’t leaked any air
  25. Ride!

Troubleshooting

I’m not sure what rim tape width to buy

The general consensus is to go for 2 mm bigger than the rim width. If you want to be absolutely sure, here’s what I came up with, and did:

Cut a small piece of office tape and place it across on the rim, starting from one edge/sidewall, going down the channel and ending on the other edge/sidewall. Press the tape down firmly so that it follows all the rim channel surface. Use a permanent marker to mark the side walls. Remove the tape and stick it on a piece of paper. Use a ruler to measure the width! ;-)

I have a hard time removing the tires from the rims

After deflating the tire, and before using tire levers, grab/pinch the tire and pull with force to the center of the rim. Repeat the process around the tire. Eventually this will break the bead and cause it to sit on the channel, introducing some slack to the tire. Repeat the processes with other bead. Now use tire levers to remove one bead. Remove the other bead towards the same direction! It really helps to have wide and strong tire levers for this.

Watch this.

I’m not sure how to tape the rim

Go slowly. Use a headlamp. Grab the wheel close to you so that working on it is easy. One way to do it is to align one edge of the tape with one rim sidewall and press down, then move to the channel, and press down as well. Leave pressing down the other sidewall for the end. This will make it possible to run through the whole tape at the end to remove any trapped air and set the tape better. The tape should be strong, sticky and flexible.

Watch this.

I have a hard time installing the tires on the rims

Place the bead starting from the valve and work your way around with both hands. When things get tight, go down the valve and pull the tire upwards to create some slack, again working your way around with both hands while pulling. Then go to the middle of the tire where it hasn’t been seated yet and pull and rotate/twist it firmly to the opposite side, holding it down on the rim to secure it. With the other hand, use a tire lever to install the tire on the rim, starting from the edges, alternating between them, and working towards the center.

Watch this.

I’m not sure how to add tire sealant

Before adding the sealant, shake the sealant bottle vigorously and for at least 30 seconds to ensure the latex particles are evenly distributed. Wait a little for the foam to settle before adding it.

Watch this.

I cannot get the tire bead to seat/lock on the rim when pumping

You may have done a poor soap job on the sidewalls so the beads won’t slip. Or you are not pumping hard/fast enough. Or the tire is new and has uneven edges from being folded. Another idea is to use an air compressor or a floor pump with an air chamber that stores and releases pressurized air at once.

The valve is leaking after pumping the tire

Make sure you’ve pressed down the valve very hard so that it sits firmly on the rim channel, creating an airtight seal. Use a tire lever for this and screw the nut with your hand while doing so. If it still leaks there are two possibilities: either your tape job was not perfect or the valve is not a good fit for the rim. For example, I had issues with Stan’s universal (the irony) tubeless valve and had success with Mavic’s UST tubeless valve which has a rectangular, wide rubber on the base that makes for a better seal.

The tire is leaking from a small hole on the tread

You probably have a used tire. Even if you didn’t get a flat tube, tires do get punctured and collect small holes as they are used. If the hole is big enough that leaking air is audible, I suggest removing the tire and patching the hole from the inside with a patch and some vulcanizing glue. Watch this for how to do it.

You could ignore it and try to plug the hole with the sealant, but I don’t recommend it. It may be the case that the tire still leaks from some other point (other hole on the tread, the sidewall or from a poor fit on the rim edge) and in this case, you will have to remove the tire and the whole process will be messy with the sealant inside.

In general, the tire will leak air through the “easiest” gap. If you fix the valve, it may leak through the tire holes. If you patch the holes, it may then leak through the rim edges.

First get an airtight seal using only the tire and the rim, and then proceed with adding the sealant through the valve (the so called “dry fit”). If you have patched the holes and there is still a leak, then trying to fix it with the sealant may indeed be your only hope (with a considerable chance of working)

The tire is leaking from the rim edge

The tire bead is probably not properly seated on the rim. Deflate and refit the tire and pump again. Use soap bubbles to help the bead seat correctly on the rim sidewall. If it still doesn’t work, it may be worth trying to plug the gap with the sealant.

I can’t do it :-(

Watch this, this and this.

Don’t give up! Going tubeless is definitely worth it and you will learn a lot while trying to do it. If everything else fails, you still have the option of going to a bike shop.

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