what am i doing wrong? went up with just a track pump when i first installed,

tubeless Schwalbe one, hunt wheels,

wont go up with a track pump
wont go up with a airshot

“almost” seats when i take the valve core out, but of course when i take the airshot off it just unseats

cleaned everything, etc etc

any tips?

make sure it has not seated and then run some fairy liquid around both sides and then have a go.

Always works for me

Washing up liquid, lay wheel on its side, or hang it, try to spread the beads outwards around the valve by pinching and twisting the tyre.

Leave the pump connected to the airshot then if it nearly seats, pump hard to finish it off.

You should be able to get the valve core back in without losing much air using your thumb to plug it.

I use this technique.

https://mpora.com/videos/AAe841roxcl6#HsJYejhgtV3dl62z.97

I find the tyre wants to jump back off the bead sometimes but even getting some of it on tightens the rest of tyre around the whole wheel and gets a better seal.

Works every time for me. Especially useful on older stretched tyres.

That may work with heavy tyres with thicker side walls but I don’t think it will do much for flexy road tyres.

neat washing up liquid?

Yes. Rub it on the rim bed to help the bead slide across and also help form a temporary seal to allow the pressure to push it across.

thanks, will try

I find that if the section either side of the valve is well seated the tyre will go up with a track pump and some high speed pump-action.

I had a similar issues with Ones. Went up fine the first time, but after a few months they wouldn’t reseat again. I got them to work by increasing the depth of the rim bed slightly and making them a tighter fit. I just ran a few layers of insulation tape around the rim bed, they went up fine after that.

Is this a brand new tyre or a used one?

If it’s used has it got a hole in it? Has it gone down when it was on the bike?

New, mine went on fine. Then I got a puncture on the back. I tried to put it back on back home with a compressor but couldn’t. I need to find the hole and repair it to get it to work again tubeless.

My experience is that they are not as robust as mtb tubeless.

a layer of electricians tape seemed to have helped, plus my track pump was borked so i got a flash charger, less faff then the pump/airshot imho, easier to put a few extra psi in after you release the air