Originally Posted by
oldveloman
Raleigh-built Triumph, BSA and other brands used the same frame as their Raleigh stablemates. From de sixties onwards, the tubes from the top of the seat tube to the dropouts got a smaller diameter.
Pretty sure @
Ged117's Triumph is transition era-Ti; it has the thicker stays.
I wouldn't be surprised at all if the Panaracer Col de la Vies had something to do with it.
-Kurt