I am doing the bike leg of a work triathlon tomorrow. I have stuck some halo twin rail 700×38 tyres on my arch rims. The sticker on the rim says not to exceed 45psi or something but I guess that’s aimed at tubeless?? I’m running tubes so is 65 okay??? Genuinely haven’t got a clue.

That’ll be fine. The 45psi is, as you say, related to tubeless.

Cheers. Thought so, it was a confidence check. I now have confidence this may happen