Hi. Busy converting wor lasses bike to tubeless. Its got the bonty tubeless wheels so i'm using the bonty rim strips/valves/tires/sealant. The front went on relatively straight forward once id realised that the rims and strips were asymetric 😳 The valve did leak a little but after a bit of faffing it worked.
The rear will not seal at the valve though 👿
Any thoughts? I'm going slightly mad here

You mean it is leaking around the valve but the bead is seated? Or the bead will not seat?
Am guessing that it is leaking around the valve, as long as the o-ring is still there does nipping up the retaining knurled nut thing not help? Or have you toiled on it with pliers and deformed the rim strip?
Which rims is it? My Rhythms are asymmetric but the rim strips (Bonty ones) were symmetrical. Quite hard plastic.

Isn't the seal made by the valve onto the rim strip done by an o-ring? The only things I can think of are, the hole in the strip has been slightly enlarged during installation or you need to tighten the valve up a bit more so the o-ring is squashed a bit more into the gaps!

I used the bonty strips on 717's with their valve – ended up 'gluing' the valve in with copydex and letting it set overnight – sealed spot on. With another set of wheels I did not bother with the bonty valve and just used ones cut from an old tube – got a seal straight away.

I thought that the front Bonti strip was symetric and the rear was asymetric?
I don't know if this is relevent but ….

It didn't matter to me as I used them on WTB Laserdiscs and they worked a treat.

It's leaking from the valve, the tire seems fine. Will take it all off and try again. Both wheels are asymetric

Have you got the o ring in place?