So I’m fairly new to tubeless, came on new bike and loving it. Bought new tyre, nobby nic to go on stans arch ex. Fitted and sealing no problem but I cannot get the tyre to sit correctly on the rim. The rim has an inner and outer groove tye bead can sit in and I can’t get it to sit in the outer one, where it should be, all the way round. Hence non round wheel and bumpy ride. Any similar experiences or suggested solutions would be much appreciated. Cheers.

First thing is always, does it only have the yellow tape/equivalent on it? Sometimes people tape over cloth rim tape and it doesn’t work.

How much air have you used? Quite often, a tyre’ll need quite a lot of pressure to pop it on. (but also, pressure can push the tyre on harder in the wrong place… so deflating and inflating can help)

Original set up by shop, looks like a proper job using stans stuff. Have tried pressure up and down a couple of times, will try again and go harder!
Seems odd to me that the tubeless specific rims have an inner groove for the bead to get stuck in.

…and use soapy water (or even proper tyre soap) to lubricate the tyre beads and help them slip into place.

^^^This^^^
For tight fitting tyres I bought one of those cheap plant sprayers, (the little hand held ones for about £1), filled it with a mix of water and washing up liquid, then spray the tyre bead before you inflate it. They pop on easily at about 20-30 psi but pump up beyond that and leave them for a bit.

Thanks folks, sorted with high pressure 70psi! A couple of spectacular pings later and we’re all good. Did use soapy water first time but maybe not enough.

Remember to reduce the pressure back down to around 30psi lol! 😀