clubber - Member
"How did that happen? Once fitted, there's no way that the tyre bead could get between the rim strip and the rim."
You're right, I must have imagined it
clubber - Member
"My theory on this is what I was touching on above - the the sealing on ghetto is very marginal around the valve - or at least it can be depending on the tube."
Nah, there was sealant everywhere round the rim where it was burping. It was the lack of a bead hook, the tyre was too free to move away from the edge of the rim. I'm sure building up the tyre a lot with tape could have helped but it all starts to become a titanic faff after a while and I'd wasted enough time on it tbh