Gravel setup, 40mm tyre on a 23mm internal hookless rim, tubeless with about 60ml of sealant. On dry hardpack corners at 25 psi the front lets go of a burst of air and I lose maybe 3 psi each time. The bead is seated evenly all the way round and the rim tape looks intact.
Sixty millilitres is light for a 40mm tyre. Go to 80 or 90. Sealant will not stop a burp but it stops a burp turning into a full deflation, and yours is probably getting thin anyway.
Top it up every three months or so in a dry climate, sooner in the heat. Shake the wheel next to your ear - if you cannot hear it sloshing, it is gone.
It went in about four months ago, so that is overdue by most people's numbers.
Weigh yourself with kit on and use a pressure chart rather than a number a friend gave you. Most burping I see is people running pressures they read about for a 70kg rider while weighing 95.
Soap the bead line too, just to confirm it is only burping under load and not weeping constantly.
@chain_wear_chase · 2mo ago · 3 replies
Hookless rims at low pressure need a tighter bead fit than hooked ones, and 40mm at 25 psi on a 23mm internal is right at the edge where a burp is normal rather than a fault.
What actually helps, in order:
Reply
Report
@chain_wear_chase · 2mo ago
It is the standard answer for a loose fit. Just make sure you can still get the tyre on afterwards.
Reply
Report
@rust_rescue_rin · 2mo ago
Two wraps of tape being a genuine fix rather than a workaround is not what I expected.
Reply
Report