How to Set Up Tubeless Tyres on Carbon Wheels

A good tubeless carbon wheel setup starts with the right tyre and rim combination, followed by careful preparation. Clean tape, a properly fitted valve and evenly seated tyre beads make the difference between a dependable setup and one that loses pressure overnight. The process is similar for road and gravel wheels, but compatibility, sealant quantities and pressure limits depend on your specific equipment.

1. Check tyre and wheel compatibility

Before removing packaging or fitting tape, confirm that both the wheel and tyre are approved for tubeless use. Adding tape does not make an ordinary carbon clincher rim suitable for tubeless.

Check these details in the manufacturers’ current instructions:

• Wheel diameter: Tyre and rim bead seat diameters must match. For example, a tyre marked 40-622 fits a compatible 622 mm rim.
• Tyre width: The tyre must fall within the permitted range for the rim’s internal width.
• Rim design: Establish whether the rim is hooked or hookless.
• Approved combinations: Check any tyre compatibility lists or restrictions published for your wheel model.

Hookless rims require tyres specifically approved for hookless use. A tubeless marking alone does not establish compatibility.

The ETRTO recommendations for tyres and rims provide industry guidance, while your wheel and tyre manufacturers’ instructions identify the requirements for your equipment.

2. Gather your equipment and prepare the rim

You will need compatible tubeless rim tape and valves, suitable sealant, a floor pump with a pressure gauge, clean cloths and the rim manufacturer’s approved cleaner. Keep plastic tyre levers, a valve core tool and a sealant measuring bottle or compatible injector nearby.

Choose valves long enough to leave sufficient stem exposed above the carbon rim for your pump head. Their rubber bases must also suit the rim’s internal profile.

Remove the old tyre and inspect the rim, especially the edges and the surfaces where the tyre beads sit. Stop if you find cracks, exposed fibres or damage that needs assessment.

Factory fitted tubeless tape can remain if it is the correct specification and is undamaged and firmly bonded. Replace tape with lifted edges, tears, wrinkles that compromise sealing or excessive deformation around spoke holes.

If retaping, remove old tape and adhesive carefully. Clean with a product approved for that rim, then let the surface dry completely. Avoid metal scrapers and unapproved solvents.

Some rims have sealed beds without spoke holes and may not require tape; follow their instructions.

3. Apply the tubeless rim tape

Use the tape width, thickness and number of wraps specified for your rim. Tape often needs to be wider than the rim’s stated internal width because it must follow the recessed channel.

The aim is continuous coverage of every spoke hole, with securely bonded edges.

1. Start at the position specified by the wheel or tape manufacturer.
2. Apply the tape under steady tension, keeping it centred.
3. Work it into the channel without trapping bubbles or creating folds.
4. Complete the prescribed wraps and overlap.
5. Press firmly around the full circumference, including the edges and overlap.

Extra layers alter the fit between tyre and rim. Follow the specified arrangement instead of adding tape repeatedly to tighten a loose tyre.

Make a small, neat opening directly over the valve hole using the recommended method. Avoid cutting a large opening or scoring the carbon underneath.

4. Fit the tubeless valve

Insert the valve from inside the rim and seat its rubber base squarely against the taped rim bed. Fit any supplied spacer or washer in the correct orientation.

Hold the base in position while tightening the retaining nut by hand, following the valve manufacturer’s instructions. Excessive tightening can distort the seal or damage the tape.

Use any wheel specific valve hardware supplied, including pressure relief nuts where required.

Check that the valve core is secure and the valve sits straight. If it leaks later, inspect the fit and tape before tightening the nut further.

5. Mount the tyre and add sealant

Check the tyre’s rotation arrow, then fit the first bead. The bead is the reinforced edge that locates against the rim.

Fit the second bead while keeping the sections already installed in the rim’s recessed centre channel. This creates the slack needed to lift the remaining section over the rim edge. Finishing near the valve usually helps because the valve base otherwise obstructs the channel.

Use your hands where possible. If necessary, use a suitable plastic lever carefully, protecting both the tape and tyre bead. Stop if fitting requires excessive force and recheck compatibility and bead position.

Shake the sealant thoroughly and measure the quantity recommended for your tyre size and sealant product. Wider gravel tyres generally require more than narrow road tyres, but there is no universal dose.

Choose the filling method suited to your sealant:

• Pour directly into the tyre: Leave a short section of the second bead unmounted, add sealant, then finish fitting while keeping the liquid away from the opening.
• Inject through the valve: With the tyre fully deflated, remove the valve core and inject sealant if the product permits it. Refit the core before inflation.

Some sealants containing large particles require direct pouring. Avoid mixing different formulations unless their manufacturers confirm compatibility.

6. Inflate within the permitted limits

Write down the applicable tyre and wheel pressure limits before pumping. Wheel limits may vary with tyre width, and hookless combinations require particular attention.

Never exceed the lowest applicable maximum, including during bead seating. Observe any separate mounting pressure restriction and the limits of other components in the system. A pressure printed on the tyre does not override a lower wheel limit.

Start with a floor pump and monitor the gauge continuously. Wear eye protection and keep your face away from the tyre’s sidewalls.

If the beads will not seat

Stop and check that the beads are correctly positioned and the valve base sits between them. Apply a small amount of approved tyre mounting fluid if permitted.

Some combinations need faster airflow from a tubeless booster or regulated compressor with suitable pressure control and a gauge. Faster airflow helps establish the seal; it does not justify exceeding the pressure limit.

If the tyre still refuses to seat within its permitted limits, deflate it and investigate the fit, tape and compatibility.

Inspect both beads

A popping sound can accompany seating, but sound alone does not confirm correct installation.

Inspect both sides around the entire wheel. Where the tyre has a moulded witness line near the bead, it should run evenly beside the rim. Look for sections buried below the rim edge, bulges or uneven seating.

If anything looks wrong, fully deflate the tyre before adjusting it. Never try to lever a pressurised bead into position.

7. Distribute sealant and check for leaks

Rotate the wheel, then hold it horizontally and gently tilt it around its circumference. Repeat with the other side facing upwards so sealant reaches both sidewalls and bead interfaces.

Check for persistent hissing or escaping sealant. Manufacturer approved leak detection fluid or mild soapy water, where permitted, can reveal escaping air.

Bubbles at the valve core suggest a core sealing problem. Air escaping around the valve base, spoke holes or rim vents can indicate a tape or valve seal failure.

For air escaping through the rim cavity, stop inflating and fully deflate before inspection. Keep rim vents open; sealing them does not repair the underlying leak.

8. Complete the checks before your first ride

Set a riding pressure suited to your total load, tyre size and terrain, within the permitted operating range. Maximum pressure is a limit, not a target.

Before riding, confirm that:

• Both beads are evenly seated, with no bulges or visible damage.
• Pressure remains stable during your checks.
• The wheel is securely installed and the inflated tyre clears the frame and fork.
• Sealant has been cleaned from the rim, brake surfaces and rotor.

Once these checks pass, take a short local ride, following any manufacturer instructions for an initial sealing ride. Recheck pressure afterwards and before the next outing, including the following day.

A small initial pressure drop can occur as a setup seals. Rapid or repeated substantial loss needs investigation. Carry suitable puncture repair equipment, and check sealant at the product’s recommended intervals so the tyre retains enough liquid to seal future punctures.