Tubeless Conversion: Guide for MTB, Gravel & Road
Tubeless means no inner tube, with sealant in the tyre instead. It saves weight, protects against small punctures and allows lower pressure, which means more grip and comfort. Converting is quite doable but takes more care than an ordinary tyre change. Here are the parts checklist, the steps and the most common mistakes.
Contents
Advantages and limits
- Fewer flats: Sealant closes small holes, for example from thorns or splinters, often without you noticing.
- Lower pressure possible: Without a tube there are no pinch flats (“snakebites”). You can run about 0.2 bar (2.9 psi) less on an MTB and up to roughly 10 percent less on a road or gravel bike. You will find matching starting values in the guides for MTB, gravel and road.
- Slightly less weight and lower rolling resistance, especially compared with cheap butyl tubes.
- Limits: Mounting is fiddly at first, sealant makes a mess, and sealant does not close large cuts. That is why a spare tube or a tubeless repair kit (plugs, “bacon strips”) belongs in your saddle bag.
What you need
- Tubeless-compatible rims and tyres (“Tubeless Ready”, “TLR”, “TL”). Tyres without tubeless approval are not airtight enough and can come off the rim.
- Rim tape (tubeless tape): It should be as wide as the inside of the rim bed, or 2 to 4 mm wider. Many rims come from the factory without spoke holes in the rim bed; then you do not need tape.
- Tubeless valves of the right length, with a rubber seal at the rim bed. With carbon rims and deep profiles, watch the valve length.
- Sealant: Guide amounts per tyre are about 25 to 40 ml for road, 40 to 60 ml for gravel and 60 to 90 ml for MTB. The sealant manufacturer's figure takes priority.
- Pump with a big burst of air: compressor, booster track pump or a dedicated tubeless pump. An ordinary track pump often only works with very well-matched tyre and rim combinations.
- Soapy water (washing-up liquid in water), a knife or awl, a towel, tyre levers, a rag and brake cleaner or alcohol for degreasing.
Mounting step by step
- Remove old tyres and tubes, clean and degrease the rim bed thoroughly. Remove all traces of old rim tape and adhesive.
- Apply the rim tape: Start opposite the valve hole, pull the tape taut, press it into the middle of the rim bed with your thumb and overlap about 10 cm past the valve hole at the end. Two layers make sense on most rims; one is enough on very deep beds. The tape must not form bubbles.
- Pierce the valve hole (small awl or knife tip, from inside to outside), insert the valve and tighten the nut by hand. The rubber should sit flat and tight against the tape.
- Mount the tyre: Seat one side of the tyre fully in the rim, mind the direction of rotation. Seat the second side too, finishing opposite the valve, where the rim bed is deepest. That saves effort.
- Wet the beads: Brush soapy water onto both tyre beads. It helps the tyre slide into the rim hooks and later shows leaks.
Inflating and sealing
- Unscrew the valve core (if possible). That greatly increases air flow.
- Inflate with a burst: Put the compressor or booster on the tyre immediately until it “pops” loudly twice and the bead jumps into the rim hook on both sides. Do not exceed the maximum pressure stated on the tyre and rim, not even briefly. Hookless rims have special limits.
- Add the sealant: Either through the open valve with a syringe or bottle, or, if the tyre is not seated yet, directly into the tyre before closing it. Then screw the valve core back in.
- Bring the pressure to riding pressure and turn the wheel in all directions, tilt and shake it so the sealant spreads everywhere. If sealant leaks out, lay the wheel with the leak at the bottom.
- Ride a lap or leave the wheel for a few hours. Check the pressure the next day; a small loss in the first days is normal.
Troubleshooting
| Problem | Likely cause | Remedy |
|---|---|---|
| Bead does not jump into the rim hook | Too little burst, dry beads, tyre seated crookedly | Remove the valve core, apply soapy water, use a booster or compressor, push the tyre to the middle of the rim |
| Air escapes at the bead | Tyre not seated tightly yet, dirt in the rim hook | Spin the wheel, spread the sealant, build pressure again, clean the rim hook |
| Sealant leaks at the spoke holes | Rim tape leaking or too narrow | Remove the tyre, renew the tape, choose wider, add a second layer |
| Sealant “sweats” through the sidewall | Porous tyre | Spin the wheel and leave it; the pores usually close after a while |
| Air escapes at the valve | Valve nut loose, rubber sits crookedly | Realign and tighten the valve, replace if necessary |
| Tyre loses air in corners (“burping”) | Too little pressure or too little sealant | Raise the pressure, top up sealant, check rim width and tyre width |
Maintenance
- Top up sealant: every two to three months, sooner in hot weather. You can track the interval in the digital garage My bike; “Check tubeless sealant” is preset there every 90 days.
- Check: Occasionally open the valve or the tyre and see whether the sealant is still liquid. Remove clumped residue with your finger.
- Check pressure: Tubeless tyres lose air slowly. Check the pressure before every ride.
Safety note: Always follow the instructions of the rim, tyre and sealant manufacturers, especially for maximum pressure, mounting and combinations. If in doubt, have a workshop mount the tyres.
Frequently asked questions about converting to tubeless
What parts do I need for tubeless?
Tubeless-ready rims and tyres, rim tape of the right width, tubeless valves, sealant and a pump with a strong burst of air, for example a compressor or a booster track pump.
How often do I need to top up sealant?
About every two to three months, sooner in hot weather and with high mileage. The sealant dries out and then no longer seals reliably.
Why is my tubeless tyre losing air?
Usually at the bead (tyre not seated tightly), at the spoke holes (rim tape leaking), at the valve or through tiny pores in the sidewall. Soapy water and a ride with fresh sealant almost always fix it.
Calculate the right tyre pressure →