Yeah but how do they inflate without an inner tube?
I'm guessing they're tighter to fit than normal tyres.
I heard somewhere you gotta use really fast inflation pressure...
Depends on your rim/tyre combo but mostly luck to be honest. Has got a lot easier as rim companies have got the designs sorted.
Most combo’s go on with just a track pump these days. Also have an Airshot tubeless inflator canister for stubborn pairings. Was £50 but if you are mechanically minded you can make one from an old fire extinguisher or fizzy drinks bottle. Plenty of vids on you tube but I’d rather have a properly engineered solution and not a home made bomb pumped up to 160psi! Tends to be more an issue when refitting used tyres as they’ve stretched slightly or have dried mud or sealant preventing a quick seal. Some people use soapy water to help the tyre slip, but never had much success with this myself.
I do also have on set of wheels immune to even the airshot. Plus bike wheels are 40mm rims and 2.8 tyres and struggle to seat. For these I use the inner tube method.
Fit as if using tubes, this snaps the bead into place. Carefully break seal on on side of rim and remove inner tube. Fit valve the use the above methods. Having one side of tyre seated makes it easier for the other to seal.
Best method is if you are lucky enough to have access to a proper air compressor. These snap them in place in no time.
I agree with
@Russell , seat the tyres properly then deflate and add sealant through valve. Seen too many photos of what happens when the tyre pops off, spraying sealant everywhere. Last thing you want is a pearl necklace from Stan.
Depending on how the tyres are packaged, try to leave them unboxed but shaped overnight. You can you this with an inner tube to help push out any folds or creases. Tends to be worse with Maxxis as the insist on folding them over the packaging tab and zip tying them in place.
One last thing to remember. They will need ridden to help everything bed in and distribute the sealant. If you do it late at night, fully expect a disappointingly flat tyre in the morning. If you can, go for a short ride, bump up and down some kerbs and do heavy braking. Gets the fluid in all the nooks are crannies. After the ride, put them to a known pressure and let sit at least overnight. Check pressure before next ride to check.
Good luck with it. It’s a lot easier than I’ve made it sound, just be patient and do it when you’ve plenty of time, not the night before a big ride. Let us know how you get on.