I always thought this tubing was pretty good. The mixte version of the Raleigh Olympian is one of the best mixte frames available, in my experience - and that's partially owing to the decent quality tubing. It was surprisingly light, although I couldn't give you an exact measurement. I know a couple people who really love theirs, both mixte version and regular diamond frame. I spread one Raleigh Olympian 575sl mixte to 135mm and it was much stiffer and harder to do than your average hi-tensile frame. Felt a bit more like a midlevel Japanese bike, but not quite as stiff as a 531 rear triangle. I felt one of these bikes was good enough to justify brazing on some canti posts and rack mounts for the owner.
H
ere's another thread about it, in case you haven't seen it.
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Owner & co-founder, Cycles René Hubris. Unfortunately attaching questionable braze-ons to perfectly good frames since about 2015. With style.