Installing new tubeless tires can be frustrating when you can’t get the beads to seal and seat properly on the rim.
No matter how much air you pump in, it just wheezes out from the edges and the tire remains flat and floppy. But don’t despair!
You can get even the most stubborn tubeless setups sealed and inflated.
This article will cover the potential causes of why tubeless tire won’t seat and show you how to help your new tires pop into place.
What Causes A Tubeless Tire To Not Seat Properly?
A tubeless tire failing to seal and seat onto the rim when inflating can be caused by a variety of factors.
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Here are some of the common ones:
Air Pressure Too Low
If the inflation pressure is not high enough, the tire bead tension and elastic force may prevent the beads from popping outward onto the rim ledges designed to hold them in place.
Sufficient pressure is required to overcome the resistance of the bead.
A hand pump without a large reserve air tank may not be able to supply enough volume to quickly inflate the tire and seat the beads before air leaks out.
More air volume allows higher inflation pressure to expand the beads outward.
Sealant Or Lubricant Residue
Residue from sealants, oils or greases can coat the tire beads and rim bed.
This contamination prevents the necessary air-tight seal between the tire beads and rim.
Even small amounts of lubrication can cause sealant failure and air leaks through the bead area.
Rim Or Tire Bead Damage
Any damage, dents or irregularities anywhere along the rim bed can allow air to escape between the tire and rim interface.
Frayed, loose or damaged tire beads are another culprit for loss of air pressure and inability to seal against the rim.
Even minor damage around the entire bead circumference can prevent proper seating.
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What To Do If Tubeless Tire Won’t Seat?
Here are some tips to seat a tubeless tire that won’t seat:
Use Soap Water To Help The Bead Seal
Applying some soapy water or a tubeless tire sealant around the tire bead prior to inflation can help it slip into the proper sealing position on the rim.
Mix together a couple tablespoons of mild dish soap with water in a spray bottle, but avoid harsh detergents.
Then spray or brush this soapy solution onto the tire bead and rim surface on both sides of the wheel.
The soapy water will act as a lubricant and allow the bead to slide into place smoothly when air pressure is added.
Also Read: Do Bike Tires Deflate Over Time?
Check Air And Volume
Floor pumps often don’t provide enough volume and PSI to fully seat a tubeless tire.
You can try using an air compressor, if one is available, to generate the extra volume and higher pressures needed to pop the tire bead into place.
Make sure the compressor can output at least 50-60 PSI. CO2 inflators are another option that provide a quick burst of high pressure air which can help seat the bead.
One affordable and effective solution is the Park Tool Shop Inflator.
This tool connects to a standard air compressor but uses an internal system to boost the air volume being pumped into the tire. This increased airflow is often the key to finally getting a stubborn bead to seal properly.
When using any high-volume inflator, listen closely for the bead popping into place as you pump up the tire.
Make sure to visually inspect both sides of the wheel to confirm that the tire bead has seated evenly all the way around the rim before stopping.
Wrapping a ratchet strap around the wheel to compress the tire bead can assist the air pressure in fully popping it into place.
Also try to put the tube in the tire and inflate to around 40 psi. Leave for an hour or more.
This can help the tire beads stretch and conform to the rim shape.