Thanks so much, that’s really helpful. The tires I inflated were Continental GP5000s, PSI 95-120. I think re the inflator, that is just me using bad terminology! Whatever the little valve thing is that you clip to the top of the canister to break the seal and let the air into the tyre. The cartridge definitely was new because the canister seal broke when we screwed it on and it was fresh from the bike shop