After a lot of swearing and the old ‘seat the beads with an inner tube’ trick I finally got a pair of Continental Trail King 29er tyres (2.2, Racesport, Black Chilli) onto my Stan’s Arch EX rims. Pumped ’em up to 60psi, rode up and down the street a bit to spread the Stan’s sealant around and popped the bike back in the shed, ready for the next days’ ride. Next day, while the front is a little softer, the rear is as flat as buggery. So I pump it up and go ride (Blue-Red-Blue round Swinley). I have to stop to add air to the rear 4 times in a 2-hour ride and I notice sealant gently coming out of a few places where the bead seats against the rim. “It’ll settle down” I tell myself. I get home, pump it up to 60psi again and leave it overnight… Totally flat the next morning. The front seems fine. What to do? Is it as simple as adding more sealant? And please, resist the urge to suggest a return to 26″ wheels or inner tubes. It ain’t gonna happen. Ta.

Conti recommend you do this for tubelessing their tyres. RaceSport ones are a bit flimsy too.

[video]http://www.youtube.com/watch?v=1HfULR0PnZE[/video]

Did you clean the inside of the carcass with anything? Whatever Continental use as a mould release agent also does a very good job of stopping sealant from sealing!

I just had exactly the same with same 2.2 tyre and less so but also with the 2.4 trailking for the front. Take em off, save your gunk then wipe the inside of the tyre with disk brake cleaner to remove the polymer residue that is preventing your gunk from sealing the tyre, dry them and refit with gunk, then will be fine

Ah! Very helpful. Thanks all.

I had the same issue (with protection though the race sports were rubbish on the sidewalls and i cant imagine them being fun tubeless, have fun with that)

Anyways i found i could get them up and airtight with a few days straight out of the packet. Result but the fact they needed pumping up every few days annoyed me. I re seated them and added more sealant to no avail. I ended up with twice the amount in the rear it should have needed. Anyhow one evening i was reseating them and i used the washing up liquid method. I had not needed it before as they went straight up and i was worried about a bit of water in the tyre. Anyhow sealed a treat now. They do loose about 2-4 psi a week though which is still a little annoying.

Success!

I unseated the bead on one side of the rim, did a version of Continental’s scrub-the-sidewalls-with-sealant technique, added a couple more capfuls and prayed as I re-inflated. I took it up to 55psi, shook the daylights out of it and rested it on a bucket to let the sealant impregnate the sidewalls (switching sides every half hour or so for a couple of hours). My hopes weren’t high as when I gave the rim a clean off, water spilt onto the tyre showed air leaking out of the sidewalls! However 48 hours later the tyre is still hard. Victory! Thanks for all your suggestions.